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i,C  THE 

JlNATOMICAI.   REMEMBRANCER; 

OR, 

Complete  foclut  gmatomist: 

CONTAINING 

A   CONCISE    DESCRIPTION   OF   THE     BONES,   LIGA- 
MENTS,   MUSCLES,   AND   VISCERA; 

THK   DISTKIBUTION   OF  THE 

Nerves,  Blood- Vessels,  and  Absorbents  ; 

THE  ARRANGEMENT  OF  THE  SEVERAL  FASCIiB  ; 

TBS 

ORGANS  OF  GENERATION  IN  THE  MALE  AND  FEMALE, 
AND  THE  ORGANS  OF  THE  SENSES. 


CtBbtb  €n\t\0n. 


NEW  YORK : 
WILLIAM  WOOD  &   CO. 

1877. 


ql^l^f 


A  5i 

PREFACE  TO  THE  EIGHTH  EDITIOIJ. 


This  work  has  rapidly  passed  through 
several  editions,  and  in  issuing  another 
the  editor  has  endeavoured,  without  any 
material  alteration,  to  preserve  the  original 
character  of  the  work,  and  make  it  calcu- 
lated to  assist  alike  the  practitioner  and 
the  student. 

The  present  edition  has  been  carefully 
revised  throughout,  and  those  alterations 
which  have  seemed  desirable  have  been  in- 
troduced in  their  proper  places. 


October,  1876. 


^' 


Digitized  by  tine  Internet  Archiv 

in  2007  with  funding  from 

IVIicrosoft  Corporation 


http://www.archive.org/details/anatomicalremembOOnewyricli 


INDEX. 


PAOB 

Minute  Structure  of  Bone    ...  1 

The  Spinal  Column      ....  3 

Common  characters  of  a  true  vertebra       .  4 

Characters  of  the  cervical  vertebra        .  5 

Deviations 6 

Characters  of  the  dorsal  vertebrae  .        .  8 

Deviations 9 

Characters  of  the  lumbar  vertebrae        .  10 

Deviations H 

False  vertebrae 12 

Os  sacrum 12 

Os  coccyx 1^ 

Spine  as  a  whole 1* 

The  Thorax ^^ 

Common  characters  of  a  rib      .        .        .16 

Deviations ^' 

The  sternum ^^ 


The  Pelvis 


19 


Os  ilium 20 

Os  pubis 21 

Os  ischium 22 


The  Bones  of  the  Superior  Extremity 
The  Bones  of  the  Lower  Extremity 
The  Sesamoid  Bones 
The  Skull  and  Face    . 

Occipital  bone   . 

Parietal  bone 

Frontal  bone     . 

Temporal  bone 

Sphenoid  bone  ; 

Ethmoid  bone 

Malar  bone 

Superior  maxillary  bone 

Palate  bone 

Inferior  spongy  bone 

Lachrymal  bone 

Nasal  bones   . 

Vomer 

Inferior  maxillary  bone 

Os  hyoides  ..... 
The  Cranial  and  Facial  Sutures 
The  Orbits  ..... 
The  Temporal  Foss^  . 
The  Zygomatic  Foss^  ;  .  , 
The  Pterygo-Maxi-llary  Fissures 
The  Nasal  FossiE  .... 
The  Articulations 

Temporo-maxillary  articulation 

Occipito-atJoid  articulation    . 


PAGIB 

24 


Occipito-axoid  articulation 
Atlo-axoid  articulation  . 
Common  vertebral  articulation 
Costo-spinal  articulation 
Costo-sternal  articulation  , 
Lumbo-sacral  articulation 
Ilio-sacral  articulation 
Sacro-coccygeal  articulation  , 
Pubic  articulation     . 
Sterno-clavicular  articulation 
Scapulo-clavicular  articulation  . 
Coraco-clavicular  articulation 
Ligaments  of  the  scapular 
Humero-scapular  articulation 
Humero-cubital  articulation 
Superior  radio-ulnar  articulation 
Inferior  radio-ulnar  articulation 
Radio-carpal  articulation 
Carpal  articulations  . 
Carpo-metacarpal  articulations 
Metacarpo-phalangeal  articulations 
Inter-phalangeal  articulations 
Ilio- femoral  articulation    . 
Femoro-tibial  articulation 
Tibio-fibular  articulation  . 
Articulation  of  the  ankle 
Articulations  of  the  tarsus 
Tarsoymetatarsal  articulations 


Cemcal  fascia 

Superficial  fascia  of  abdomen 
Fascia  transversalis  and  fascia  iliaca 
Superficial  perineal  fascia 
Triangular  ligament  of  the  urethra   , 
Fascia  of  the  upper  extremity 
Fascia  lata         .... 
The  Muscles  .        .        .        •        . 
Muscles  of  the  head  . 
Muscles  of  the  external  ear  . 
Muscles  of  face  .... 
Muscles  of  lower  jaw 
Muscles  on  anterior  and  lateral  parts  of  the 

neck 

Muscles  of  the  pharynx 

Muscles  of  the  palate 

Muscles  of  the  larynx    .        .        . 

Deep  muscles  on  anterior  and  lateral  parts 

of  the  neck 

Muscles  of  the  thorax    . 
Muscles  of  the  back  . 
Muscles  of  shoulder  and  arm 
Muscles  of  forearm  and  hand    • 
Muscles  of  abdomen 
Deep  muscles  of  abdomen 
Muscles  of  male  perineum 
Muscles  of  female  perineum 
Muscles  of  inferior  extremity 


PA6X 

102 
102 
103 
105 
105 
106 
107 
110 
110 
110 
110 
113 


PAGE 

Muscles  of  hip 140 

Muscles  on  back  of  thigh      .        .        .        142 
Muscles  on  anterior  and  external  part  of  ^ 

leg 

Muscles  on  outer  part  of  leg 
Muscles  of  back  of  leg   . 

Muscles  of  foot 

Muscles  of  orbit    .        .        •        • 
Muscles  of  internal  ear 
The  Brain  and  its  Membranes 

Dura  mater 

Sinuses 

Tunica  arachnoidea  .... 

Pia  mater 

Cerebrum 

Cerebellum 

Medulla  oblongata    .... 
Base  of  the  brain    .... 
Origins  of  the  crebral  nerves     . 
Distribution  of  the  cerebral  nerves 
Ganglions  in  connection  with  the  fifth  pair 
Spinal  nerves         .        .        .        . 
Cervical  plexus         .... 
Brachial  plexus      .... 

Dorsal  nerves 

Nerves  of  Wrisberg        ,        .        . 
Lumbar  plexus         •         •        .         • 
Sacral  plexus         •        •        •        • 


Sympathetic  nerves  . 

Cervical  ganglia    . 

Cardiac  nerves  . 

Cardiac  plexus 

Thoracic  ganglia 

Semilunar  ganglia 

Solar  plexus 

Renal  plexus 

Inferior  mesenteric  plexus 

Lumbar  ganglia    . 

Sacral  ganglia  . 

Ganglion  impar 
The  Thorax  and  its  Contents 

Pleurae       .... 

Anterior  mediastinum    . 

Middle  mediastinum 

Posterior  mediastinum  . 
The  Lungs 

Trachea  and  its  ramifications 
The  Heart  and  Pericardium 
The  Arteries 
The  Veins 
The  Digestive  Apparatus   . 

Mouth       .... 

Teeth 

Tongue     .... 

Tonsils 

Salivary  glands     . 


INDEX.  XI 
PAGE 

Pharynx,  and  <ESophagus   ....  232 

Stomach 233 

Duodenum,  jejunum,  and  ileum        .        .  235 

Caecum 237 

Colon  and  rectum      .        .        .        .         .  238 

Liver- 239 

Pancreas 243 

Spleen     .         .                ....  243 

Supra-renal  capsules         ....  244 

The  Urinary  Apparatus     .        .        .  245 

Kidneys 245 

Ureters    .         .                ....  247 

Urinary  Bladder        .         .                 .        .  248 

The  Peritoneum 250 

The  Male  Organs  of  Generation        .  254 

Testicles 256 

Spermatic  cord 258 

Vesiculffi  seminales  and  prostate  gland  559 

Cowper's  glands 259 

Penis 260 

Urethra 262 

The  Female  Organs  of  Generation  264 

Mammaj    .......  267 

The  Organs  of  the  Senses        .        .  267 

Organ  of  touch 267 

Organ  of  smell 269 

Organ  of  taste 271 

Organ  of  vision 271 


PAGE 

Appendages  of  the  eye      ....  271 

Organ  of  hearing 280 

Absorbent  system 288 

Peculiarities  or  the  Fcetus      .        .  291 

The  Laryxx 292 

The  Thyroid  Body      ....  296 


ANATOMICAL  REMEMBRANCER. 


MINUTE  STRUCTURE  OF  BONE. 

Bone  is  composed  of  an  animal  and  an  earthy 
portion  in  intimate  union.  The  former  (33  3  per 
cent.)  may  be  almost  entirely  resolved  into  gelatin ; 
the  latter  (66.6  per  cent.)  consists  mainly  of  the 
phosphate  and  carbonate  of  lime,  with  a  small 
amount  of  lluoride  of  calcium,  phosphate  of  mag- 
nesia, and  chloride  of  sodium.  It  is  surrounded  by 
a  vascular  fibrous  membrane  (i^eriosteum) ;  the  long 
bones  are  lined  with  an  internal  membrane  (medul- 
lary). The  outer  portion  of  a  bone  is  hard  and 
compact,  and  passes  by  degrees  into  the  inner, 
which  is  spongy  or  cancellated.  The  arteries  of 
bone,  which  are  numerous  and  of  small  size,  run  in 
small  bony  canals  (Haversian),  which  vary  from 
ToVirth  to  2u  oth  of  an  inch  in  diameter ;  the  larger 
ones,  moreover,  contain  marrow.  These  canals  are 
short,  run  chiefly  in  the  long  axis  of  the  bone, 
and  communicate  frequently  by  small  transverse 
branches,  thus  maintaining  a  free  communication 
between  the  vessels  of  the  periosteum  and  those  of 
B 


2    . 

the  medullary  membrane.  Each  Haversian  canal  is 
surrounded  bv  a  series  of  concentric  rings  (lamellae) 
varying  in  number  from  eight  to  fifteen,  among 
which  are  seen  numerous  dark  spots  called  lacunae. 
Besides  the  concentric  lamellae,  there  are  some 
which  run  parallel  with  the  outer  and  inner  sur- 
faces of  the  bona,  called  circumferential  lamellae, 
while  there  are  others  which  pass  between  the  Ha- 
versian systems,  called  interstitial  lamellae.  The 
lacunae  are  small  cavities  from  which  issue  minute 
canals  (canaliculi)  y^io o  of  an  inch  in  diameter, 
which  communicate  freely  with  the  canaliculi 
of  adjacent  lacunae.  The  Haversian  canal,  with 
its  concentric  lamellae,  lacunae,  and  canaliculi,  is 
termed  an  Haversian  system ;  and  the  spaces  seen 
between  adjoining  systems  are  called  Haversian 
spaces.  Nerves  and  lymphatics  have  been  traced 
into  the  substance  of  bone. 

The  medullary  canal,  the  cancellous  texture,  and 
the  larger  Haversian  canals  are  filled  with  marrow. 
In  the  adult  this  is  composed  of  fat  (96  per  cent.), 
fluid  with  extractive  matters  (4  per  cent.).  In  the 
articular  ends  of  long  bones,  the  diploe  and  the 
short  bones,  it  is  red,  and  contains  only  a  trace 
of  fat,  25  per  cent,  consisting  of  albumen,  fibrin, 
and  extractive  matters,  the  remainder  being  com- 
posed of  water.  In  young  bones  the  marrow  is 
also  red  and  free  from  fat. 

Bone  is  developed  mainly  from  temporary  carti- 


3 

lage,  but  occasionally  from  membrane.  The  pro- 
cess consists  in  the  deposit  of  the  earthy  salts  in 
the  interior  of  the  cartilage  at  certain  points,  call- 
ed centres  of  ossification,  from  which  it  spreads 
throughout  the  entire  mass.  The  period  of  ossifi- 
cation varies  from  the  second  to  the  eighth  month 
of  foetal  life. 

The  epiphyses  ossify  after  birth,  and  become 
united  to  the  main  bone  inversely  to  the  order  of 
the  appearance  of  their  ossification, 

OSTEOLOGY. 

The  skeleton  is  composed  of  200  bones  : — 

The  spinal  column 26 

The  cranium  and  face  ...  22 
Ribs,  sternum,  and  os  hyoides  .  26 
The  upper  extremity  ...  64 
The  lower  extremity  ....     62 

200 

The  spinal  or  vertebral  column  supports  the  head, 
and  is  supported  by  the  pelvis.  The  bones  which 
enter  into  its  formation  are  called  vertebras,  of 
which  there  ars  two  classes,  the  moveable  and  the 
united. 

The  moveable  vertebrce,  twenty-four  in  number, 
arc  subdivided  into  three  groups — viz.,  seven  cervi- 
cal, twelve  dorsal,  and  five  lumbar. 


The  United  or  Jixed  vertebrce  are  coalesced  to 
form  two  pieces — viz.,  tlie  sacrum  and  the  coccyx, 
both  of  which  bones  enter  into  the  formation  of 
the  pelvis. 

GENERAL  CHARACTER  OF  A  VERTEBRA. 

The  body,  a  mass  of  bone  forming  the  anterior 
part  of  a  vertebra.  It  is  thick,  spongy,  and  pre- 
i^ents  a  number  of  small  apertures  for  the  nutrient 
vessels.  It  is  connected  with  the  bodies  of  the 
vertebrae  above  and  below  by  the  intervertebral 
fibro-cartilages. 

Pedicles  are  two  thin  portions  of  bone  which 
connect  the  sides  of  the  body  with  the  laminae. 
They  are  grooved  above  and  below,  interverte- 
bral notches y  the  lower  one  being  usually  the 
deeper. 

Lamince,  two  lateral  plates,  w^iich  pass  back- 
wards from  the  posterior  part  of  the  body,  and 
meet  in  the  middle  line  behind  to  form  the  spinous 
process.  The  upper  and  lower  borders  are  rough, 
for  the  attachment  of  the  ligamenta  subjlava. 

Two  transverse  processes  pass  outwards  from  the 
sides  of  the  laminae. 

Four  articular  processes,  two  upon  the  upper 
and  two  upon  the  lower  surfaces  of  the  laminae  at 
the  roots  of  the  transverse  processes,  articulate 
with  the  articular  processes  of  the  vertebrae  above 
and  below. 


All  these  processes  differ  from  the  body  in  being 
formed  of  more  compact  bony  tissue. 

Four  notches^  two  above  and  two  below,  which  • 
are  formed  by  the  laminae  being  grooved  out  where 
they  join  the  body.  Each  of  these,  with  the  cor- 
responding notch  above  and  below,  forms  a  lateral 
hole,  the  intervertebral  foramen,  for  the  exit  of  the 
spinal  nerves  and  the  entrance  of  blood-vessels. 

The  foramen,  a  ring  enclosed  by  the  body  and 
laminae,  is  called  the  spinal  canal  for  the  spinal 
cord,  with  its  membranes  and  blood-vessels. 

CHARACTERS    OF   THE    CERVICAL   VERTEBRJE3. 

\st  Their  bodies  are  small,  deeper  in  front  than 
behind,  and  long  transversely.  Their  upper  sur- 
faces are  concave  from  side  to  side,  where  they  pre- 
sent two  projecting  lips.  Their  under  surfaces  are 
convex  and  rounded  off  at  their  sides. 

2nd.   'Their  lamince  are  long,  broad,  and  thin. 

Srd.  Tlieir  spinous  processes  are  short,  horizon- 
tal, and  bifid  at  their  extremities. 

4th.  Their  transverse  processes,  also  short  and 
bifid,  are  grooved  upon  their  upper  surface  for  the 
spinal  nerves,  and  perforated  by  a  round  foramen 
at  their  bases  for  the  vertebral  artery,  vein  and 
plexus  of  nerves,  the  direction  of  which  is  upwards. 
Each  transverse  process  has  two  roots  ;  the  pos- 
terior springs  from  between  thp  articular^processes, 


6 

at  the  junction  of  the  pedicle  -with  the  arch,  as  is 
the  case  with  the  transverse  process  in  the  dorsal 
.  and  lumbar  regions  ;  the  anterior  arises  from  the 
side  of  the  body  of  the  vertebra. 

5/A.  The  articular  processes  are  large ;  their  su- 
perior surfaces  are  oval,  flat,  and  look  upwards 
and  backwards ;  their  inferior  surfiices,  also  oval 
and  flat,  look  downwards  and  forwards. 

6fA.  The  notches,  nearly  of  equal  size,  are  small, 
and  anterior  to  the  articular  processes,  as  in  other 
vertebrae,  but  are  behind  the  anterior  roots  of  the 
transverse  processes. 

7th.  The  vertebral  foramen  is  large  and  trian- 
gular. 

I>EVIATIONS. 

The  first,  or  atlas,  consists  of  a  large  bony  ring, 
enclosing  an  irregular  foramen,  which  in  the  recent 
state  is  divided  into  two  unequal  segments  by  the 
transverse  ligament ;  the  anterior  being  occupied 
by  the  odontoid  processes  of  the  axis,  the  posterior 
by  the  spinal  cord.  Instead  of  a  "  body  "  it  pre- 
sents anteriorly  a  small  arch  of  bone,  the  "  anterior 
arch,"  marked  by  a  tubercle  in  front,  and  a  smooth 
oval  surface  behind,  which  articulates  with  the 
odontoid  process  of  the  axis.  Laterally,  the  bone 
acquires  great  density  and  thickness,  and  forms  the 
*'  lateral  masses,"  which  present  upon  their  upper 
and  lower  aspects   the   articular  processes,  the 


superior  of  which,  horizontal,  concave,  and  oval 
from  before  backwards,  look  upwards  and  inwards, 
and  articulate  with  the  condyles  of  the  occipital 
bone ;  the  inferior,  flat  and  circular,  look  downwards 
and  inwards  and  articulate  with  the  second  cervical 
vertebra.  Internally  each  lateral  mass  is  marked 
by  a  small  tubercle  which  gives  attachment  to  the 
transverse  ligament.  The  transverse  processes  are 
long  and  terminate  in  a  rounded  extremity  ;  they 
are  pierced  at  their  bases  by  the  foramen  for  the 
vertebral  artery,  the  direction  of  which  is  upwards 
and  backwards  ;  behind  the  superior  articular  sur- 
face is  a  groove,  which  marks  the  course  of  the 
vessel.  The  spinous  process  is  represented  by  a 
small  tubercle  upon  the  middle  of  the  posterior 
segment  of  the  ring,  which  is  considerably  larger 
than  the  anterior. 

Tlie  second,  or  axis^  is  distinguished  by  its  large 
tooth-like  or  odontoid  process,  which  rises  from  the 
upper  surface  of  the  body.  This  process  presents 
anteriorly  an  oval  surface  for  articulation  with  the 
ring  of  the  atlas,  and  posteriorly  a  smooth  sur- 
face which  moves  against  the  transverse  ligament, 
whilst  its  apex  or  head  presents  an  enlargement  to 
which  the  check  ligaments  are  attaclied.  The 
laminic  are  very  thick  and  strong,  and  terminate 
posteriorly  in  the  spinous  process,  which  is  strong 
and  bifid ;  the  vertebral  foramen  is  heart-shaped, 
the  apex  being  posterior.     Ths  superior  articular 


8 

Surfaces  are  large,  and  slightly  convex,  and  arc 
directed  upAvards  and  outwards,  whilst  the  inferior, 
looking  downwards  and  forwards,  are  small  and 
flat,  and  are  situated  behind  the  superior  facets. 

The  transverse  processes  not  bifid  are  short  and 
directed  downwards,  the  direction  of  the  foramen 
for  the  vertebral  artery  being  obliquely  upwards 
and  outwards :  the  superior  notches  are  behind  the 
superior  articular  processes,  whilst  the  inferior 
notches  are  in  front  of  the  inferior  processes  as  ia 
other  vertebrae. 

The  seventh  cervical  vertebra  is  called  vertebra 
prominens,  from  the  length  of  the  spinous  process, 
which  projects  backwards  and  terminates  in  a 
tubercle,  to  the  extremity  of  which  is  attached  the 
ligamentum  nuchae  ;  the  vertebral  foramina,  when 
they  exist  in  the  transverse  processes,  give  passage 
occasionally  to  the  vertebral  veins  ;  the  transverse 
processes  are  often  of  such  length  as  to  resemble 
rudimentary  ribs. 

CIIARACTEKS    OF   THE   DORSAL  VERTEBRiE. 

\st.  They  are  intermediate  in  size  between  the 
cervical  and  lumbar  vertebraB. 

2nd.  Their  bodies  are  thicker  behind  than  in 
front,  and  more  convex  transversely,  presenting 
upon  their  surfaces  more  a  heart-shape  than  an 
oval  form.     On  each  side  at  the  upper  and  lower 


9 

borders  the  body  presents  two  small  depressions  or 
facets,  the  upper  being  the  larger,  which,  with  the 
intervertebral  cartilage  and  the  contiguous  verte- 
brae, form  depressions  for  the  heads  of  the  ribs. 

3rd.   The  lamince  are  broad  and  strong. 

4th.  The  spinous  processes  ara  long,  prismatic, 
tuberculated  at  their  extremities  and  directed 
obliquely  downwards,  and  overlap  each  other,  es- 
pecially from  the  fifth  to  the  eighth  vertebra. 

5th.  The  transverse  prozesses,  thick  and  strong, 
are  directed  outwards  and  backwards  ;  on  the  ex- 
tremity and  anterior  aspect  of  each  is  an  oval  sur- 
face for  articulation  with  the  tubercle  of  the  corre- 
sponding rib.  On  the  posterior  aspect  of  the  trans- 
verse processes  of  the  lower  dorsal  vertebras  are 
three  indistinct  tubercles,  named  from  their  situ- 
ation, external,  internal,  and  inferior  tubercles. 

&th.  The  articular  processes  are  nearly  vertical ; 
the  superior  looking  backwards  and  a  little  up- 
wards and  outwards,  the  inferior  forwards  and 
slightly  downwards  and  inwards. 

1th.  The  vertebral  foramen  is  smaller  than  in. 
the  cervical  or  lumbar  vertebrae  and  is  nearly 
circular. 

DEVIATIONS. 

The  1st  dorsal  vertebra  has  an  entire  facet  for 
the  head  of  the  first  rib -besides  a  demi-facet  for 
the  second  ;  its  body  is  longer  transversely  and 


10 

lipped  OD  each  side  ;  its  spinous  process  is  strong 
and  horizontal,  and  its  articular  surfaces  oblique. 
The  ^th  has  only  a  demi-facet  above.  The  lO^A 
has  an  entire  facet  upon  the  holj  for  the  corre- 
sponding rib.  The  llth  and  Vlth  have  each  an 
entire  facet  upon  the  body,  and  no  articular  facets 
upon  their  transverse  processes,  which  are  very 
short,  and  the  l2th  resembles  a  lumbar  vertebra  in 
the  shape  of  its  body,  of  its  inferior  articular 
processes,  which  are  convex  and  turn  outwards, 
and  in  the  larger  development  of  the  tubercles  at 
the  extremities  of  the  transverse  processes. 

CHARACTERS  OF  THE  LUMBAR  YERTEBRiE. 

1st.  They  are  the  largest  of  the  three  classes. 

2no?.  Tlie  bodies  are  very  broad  transversely,  of 
oval  form,  deepened  upon  their  upper  and  lower 
surfaces  by  a  more  compact  lamina  of  bone,  whicli, 
projecting  beyond  the  bodies,  renders  them 
slightly  concave  from  above  downwards  upon 
their  forepart. 

3rc/.  The  lamince  and  spinous  processes  are  broad, 
thick,  and  short. 

Ath.  The  transverse  processes  are  long,  thin,  and 
horizontal,  and  are  regarded  by  some  anatomists 
as  abdominal  ribs. 

5th.  The  superior  articulating  surfaces  are  oval, 
concave,  and  look  backwards  and  inwards  ;  the  in- 


11 

feiior  are  oval  and  convex,  directed  outwards  and 
forwards ;  and  from  each  of  tlie  superior  articular 
processes,  which  are  wider  apart  than  the  inferior, 
there  projects  backwards  the  "  tubercle." 

Uh.  The  vertebral  foramen  is  triangular  and 
larger  than  in  the  dorsal  vertebrae. 

1th.  The  notches,  particularly  the  inferior,  are 
very  large,  and  form  larger  foramina  than  in  any 
other  part  of  the  spine. 

DEVIATIONS. 

The  last  lumbar  vertebra  has  its  body  cut  off 
obliquely  upon  its  sacral  aspect,  so  that  it  is  much 
deeper  in  front  than  behind.  Its  transverse  pro- 
cesses are  long  and  rounded.  The  interval  be- 
tween the  inferior  articular  processes  equals  that 
between  the  superior  articular  processes. 

In  examining  the  peculiar  characters  of  the 
different  vertebrae,  it  is  best  to  select  one  from  the 
centre  of  each  class  ;  thus  the  ^rd  lumbar,  the  ^th 
or  1th  dorsal,  and  the  Uh  or  Uh  cervical,  afford  the 
best  examples  of  the  class  to  which  each  belongs  ; 
for  as  the  cervical  Yertebra3  approach  the  dorsal, 
they  begin  to  assume  more  or  less  the  characters 
of  the  latter,  and  the  last  dorsal  vertebra  upon  its 
under  aspect  presents  the  character  of  a  lumbar 
vertebra.  But  there  is  no  difficulty  in  determin- 
ing the  region  to  which  any  vertebra  belongs, 


13 

however  indistinctly  its  characters  may  be  marked. 
Thus,  the  transverse  processes  of  all  the  cervical 
vertebrse  are  perforated  by  a  foramen,  which  trans- 
mits the  vertebral  artery  and  vein  ;  all  the  dor- 
sal vertebra?  present  upon  their  bodies  a  smooth 
surface  of  articulation  for  the  heads  of  the  ribs  ; 
all  the  lumbar  vertebra  are  distinguished  by  the 
absence  of  these  characters. 

Development  of  a  vertebra.  Each  vertebra  has 
three  primary  centres  of  ossification — one  for  the 
body  and  one  for  each  lamina  ;  and  five  secondary 
centres — one  for  the  spinous  process,  one  for  each 
transverse  process,  and  one  for  each  circular  plate. 
In  the  lumbar  vertebrae  there  are  two  additional 
centres,  one  for  each  tubercle  upon  the  superior 
articular  process.  The  atlas  has  three  centres — 
one  for  the  anterior  arch  and  one  for  each  lateral 
mass.  The  axis  has  six  centres — one  for  the 
body,  three  for  the  odontoid  process,  and  one  for 
each  lamina. 

THE  FIXED   OE  UNITED   VERTEBRA. 

Nine  in  number  ;  the  five  upper  form  the  sa- 
crum, the  four  lower  the  coccyx. 

The  Sacrum. 

Shape,  triangular  with  its  base  directed  upwards, 

is  formed  by  the  coalescence  of  five  vertebrae.  The 

apex  presents  a  small  oval  surface  to  articulate 

with  the  coccyx;  the  base  resembles  a  lumbar  ver- 


I 

tebra  and  has  projecting  from  each  side  an  articu- 
lar process  for  the  last  lumbar  vertebra;  laterally 
the  base  extends  outwards  and  becomes  continu- 
ous with  the  iliac  fossa  of  the  pelvis  :  the  lateral 
borders  present  two  surfaces  :  the  superior,  large 
and  named  from  its  shape  the  auricular  surftice, 
articulates  with  the  ilium  ;  the  inferior  thin,  for 
the  attachment  of  the  sacro-sciatic  ligaments. 

Pelvic  or  anterior  surface,  smooth,  concave  from 
above  downwards,  is  marked  by  four  transverse 
lines  and  presents  on  each  side  of  the  median  line 
four  foramina,  called  anterior  sacral,  for  the  trans- 
mission of  the  anterior  branches  of  the  sacral 
nerves.  The  projection  which  the  sacrum  forms 
with  the  last  lumbar  vertebra  is  called  "  the  pro- 
montory." 

Dorsal  or  posterior  surface,  is  irregularly  convex, 
rough,  presenting  in  the  middle  line  an  uneven 
ridge  of  coalesced  spinous  processes  and  more  ex- 
ternally on  each  side  tubercles  of  bone  correspond- 
ing to  the  articular  processes  of  the  true  vertebrae, 
from  the  lowest  of  which  project  two  processes 
called  the  sacral  cornua:  on  each  side  of  the 
median  line  are  the  posterior  sacral  foramina  for 
the  transmission  of  the  posterior  divisions  of  the 
sacral  nerves. 

The  sacral  canal,  triangular  and  large  at  the 
base,  runs  at  the  dorsal  aspect  of  the  bone,  and 
terminates  in  a  triangular  fossa  at  its  apex,  where 


14 

it  is  bounded  on  each  side  by  a  tubercle  which  joins 
the  cornua  of  the  cocc3^x. 

Development. — The  sacrum  is  developed  from 
thirty -five  centres  of  ossification — three  centres  for 
the  body  of  each  segment,  two  for  each  lamina,  six 
for  the  lateral  masses,  and  two  for  each  lateral 
surface  of  the  sacrum. 

The  Coccyx. 

Shape,  triangular,  the  base  articulating  with  the 
sacrum. 

Anterior  surface,  smooth,  marked  by  three  trans- 
verse grooves  indicating  the  junctions  of  the  seg- 
ments. 

Posterior  surface,  rough,  for  the  attachment  of 
ligaments  and  muscles. 

Cornua,  are  two,  placed  superior!}^,  which  arti- 
culate with  the  sacral  cornua. 

The  coccyx  is  usually  composed  of  five,  sometimes 
four,rudinientary  vertebrae,  of  which  the  first,  which 
articulates  with  the  sacrum,  is  the  largest. 

Development. — By  five  or  four  centres,  according 
to  the  number  of  its  coalesced  segments. 

THE    SPIXE    AS   A  WHOLE. 

The  average  length  of  the  spine  is  about  twenty- 
seven  inches,  and  viewed  laterally  it  presents  font 
cmTCS  :  cervical,  dorsal,  lumbar,  and  pelvic.     The 


15 

cervical  and  lumbar  are  convex  anteriorly,  the  dor- 
sal and  the  pelvic  are  concave ;  the  lumbar  and  the 
pelvic  curves  exceed  the  cerv^ical  and  the  dorsal, 
respectively.  In  the  dorsal  region  moreover  there 
is  a  lateral  inclination  to  the  right  side,  usually 
ascribed  as  the  result  of  increased  muscular  action 
of  that  side. 

Form. — The  front  aspect  of  the  spine  formed  by 
the  bodies  is  seen  to  increase  in  breadth  from  the 
axis  to  the  first  dorsal  vertebra ;  at  this  point  it 
narrows  as  far  as  the  fourth  dorsal,  and  then  gra- 
dually increases  to  the  base  of  the  sacrum.  In  the 
lateral  view  the  bodies  are  seen  to  increase  gra- 
dually from  the  axis  to  the  fifth  lumbar.  Posteriorly, 
the  spinous  processes  are  arranged  in  a  linear  series, 
with  the  usual  inclination  of  some  of  the  dorsal 
spines  to  the  right  side.  On  each  side  of  these  is 
the  vertebral  groove,  shallow  in  the  cervical  and 
lumbar  regions,  deeper  and  broader  in  the  dorsal, 
and  lodge  in  the  recent  state  the  deep  muscles  of 
the  back.  External  to  the  groove  are  situated  the 
articular  processes,  and  in  front  of  these  are  the 
transverse  processes, 

THE   THORAX 

Is  formed  by  the  dorsal  vertebrce  posteriorly,  the 
ribs  and  costal  cartilages  laterally,  and  the  sternum 
anteriorly. 


16 

The  Ribs, 

Twelve  in  number,  are  divided  into  seven  true 
and  Jive  false  ;  the  two  lowest  of  the  false  being 
free  in  front,  are  called  abdominal  or  floating  ribs. 

The  true  ribs-OY  vertebrosternal  are  connected 
with  the  sternum  by  separate  cartilages. 

The  three  superior  false  ribs  have  their  cartilages 
attached  to  each  other  and  to  the  cartilage  of  the 
seventh. 

The  false  or  floating  ribs  have  their  cartilages 
free. 

Common  Characters  of  a  Rib. 

The  head,  round,  and  divided  by  a  transverse 
ridge  into  two  articular  surfaces,  the  lower  of  which 
is  the  larger.  These  are  received  into  the  depres- 
sions on  the  sides  of  the  bodies  of  the  dorsal 
vertebrae,  the  ridge  affording  attachment  to  the 
inter-articular  ligament  which  connects  the  ribs  to 
the  inter- vertebral  fibro-cartilage. 

llie  neck,  narrow  and  round ;  at  its  junction 
with  the  shaft  is 

The  tuberclcj  a  prominence  of  bone,  with  a 
smooth  surface  looking  backwards  to  articulate 
with  a  transverse  process  of  the  vertehrse  beneath, 
and  external  to  this,  a  rough  surface  for  the  attach- 
ment of  the  posterior  cos  to-transverse  ligament. 

The  shaft  is  that  portion  of  the  rib  which  extends 


■ 


17 

from  the  tubercle  to  its  sternal  end,  and  presents 
an  external  smooth  convex  surface  and  an  internal 
concave  one.  At  the  point  where  the  rib  makes 
its  sudden  curve  is  a  rough  line  which  is  called  the 
angle.  The  upper  border  of  the  shaft  is  round  and 
smooth,  its  lower  border  thin  and  grooved  for  the 
intercostal  vessels,  and  its  sternal  extremity  pre- 
sents an  oval  depression  for  the  reception  of  the 
costal  cartilage. 

Development. — From  three  centres  ;  one  each  for 
the  shaft,  tubercle,  and  head.  The  last  two  ribs 
have  only  two,  one  for  the  shaft  and  one  for  the 
head. 

DEVIATIONS. 

Tlie  First  Rib 

Is  broad  and  flat  and  placed  horizontally ;  its 
head  is  small  and  articulating  with  only  one  verte- 
bra, has  no  ridge,  and  a  single  articular  facet.  The 
neck  is  narrow  and  round  ;  the  tubercle  very  thick 
and  prominent.  It  has  no  angle  and  its  sternal 
extremity  is  thick  and  strong  ;  one  surface  looks 
upwards,  the  other  downwards  ;  the  superior  pre- 
sents a  tubercle  for  the  attachment  of  the  scalenus 
anticus,  which  separates  two  grooves — the  anterior 
for  the  subclavian  vein,  the  posterior  for  the  sub- 
clavian artery.  Behind  the  posterior  groove  is  a 
rough  surface  for  the  attachment  of  the  scalenus 
medius.  The  under  surface  is  smooth. 
c 


18 

The  Second  Rib, 

Lon^r  than  the  first,  presents  externally  an 
oblique  prominent  ridge  for  the  attachment  of  part 
of  the  first  and  the  second  digitation  of  the  serratus 
maernns  muscle.  Its  angle  is  slight,  and  it  has  a 
slight  groove  on  the  inner  aspect  posteriorly. 

The  Tenth  Rib 
Has  only  one  articular  facet  on  its  head. 

T7ie  Eleventh  and  Twelfth  Ribs 

Are  very  short,  have  neither  angle,  tubercle,  nor 
groove,  and  the  head  has  a  single  articular  facet. 

THE    STERNUM. 

Shape,  flat,  elongiited,  broader  above  than  below, 
narrower  in  the  centre,  and  is  composed  originally 
of  six  segments  ;  in  the  adult  it  consists  of  three 
portions — an  upper  or  manubrium  ;  a  middle,  the 
gladiolus  ;  and  an  inferior,  the  ensiform  cartilage. 

Anterior  surface  is  rather  convex,  and  is  marked 
by  four  transverse  lines. 

Posterior  surface,  smooth  and  concave. 

Upper  piece  or  manubrium,  quadrilateral  and 
thick,  is  concave  from  side  to  side  upon  its  upper 
border,  and  presents  at  each  superior  angle  two 


19 

semilunar  depressions  for  articulation  with  the 
clavicles  ;  its  lower  border  is  strai;:^ht  and  is  united 
to  the  second  piece ;  its  lateral  borders  receive  on 
each  side  the  cartilage  of  the  first  rib  and  half  that 
of  the  second. 

Second  piece  or  fjladiolus,  long,  narrow,  and 
marked  by  three  transverse  lines ;  receives,  by  five 
depressions  upon  its  lateral  borders,  the  cartilages 
of  the  five  inferior  true  ribs,  and  by  a  notch  at  its 
superior  angle  half  the  cartilage  of  the  second  rib  : 
its  inferior  is  thin  and  terminates  in  a  cartilaginous 
prolongation  called  the 

Eiisiform  cartilage^  which  is  sometimes  bifid 
and  pierced  by  a  foramen,  its  direction  b#ing 
variable. . 

Development. — By  six  centres — one  for  the  manu- 
brium, four  for  the  gladiolus,  and  one  for  the  ensi- 
form  cartilage. 

THE    PELVIS 

Is  formed  of  the  sacrum,  coccyx  (both  of  which 
bones  have  been  already  described),  and  the  two 
ossa  innominata. 

OS    INNOMINATUM, 

Consists  in  early  life  of  three  parts,  the  ilium, 
the  ischium,  and  the  pubes.     These  become  blend- 
ed at  puberty  so  as  to  form  a  single  bone.     Each 
of  these  parts  will  be  described  separately. 
c2 


20 

THE    ILIUM 

Is  the  upper  broad  expanded  portion  of  the  bone. 
Is  bounded  above  by  a  curved  border,  the  crest  of  the 
ilium:  it  terminates  anteriorly  in  a  projection,  the 
anterior  superior  spine  ;  posteriorly  in  an  eminence, 
the  posterior  superior  spine.  The  crest  is  divided 
into  an  external  and  internal  lip  and  an  interme- 
diate space.  Below  the  anterior  superior  spine 
and  separated  from  it  by  a  concave  border  is  the 
anterior  inferior  spine;  below  the  posterior  supe- 
rior spine  and  separated  from  it  by  a  small  notch 
is  the  posterior  inferior  spine. 

The  ala  presents  two  surfixces  ;  the  outer  or 
dorsum  is  concavo-convex  and  is  crossed  by  three 
semicircular  lines,  of  which  the  superior  passes 
from  the  crest  about  two  inches  from  the  posterior 
superior  spine  to  the  sacro-sciatic  notch,  where  it 
becomes  much  fainter;  the  middle,  the  longest, 
begins  about  an  inch  behind  the  anterior  superior 
spine,  and  curves  downwards  and  backwards  to  the 
great  sacro-sciatic  notch  ;  and  the  inferior  curves 
towards  the  lower  part  of  the  same  notch.  The 
gluteus  maximus  arises  from  the  rough  surface 
above  the  superior  curved  line,  the  gluteus  medius 
from  the  space  between  this  and  middle  line,  and 
the  gluteus  minimus  between  the  middle  and  in- 
ferior lines.  In  the  centre  is  the  foramen  for  the 
nutrient  artery.     The  inner  surface  or  venter  pre- 


21 

sents  anteriorly  a  fossa,  the  iliac  fossa,  posteriorly 
an  uneven  surface  for  articulation  with  the  side  of 
the  sacrum.  The  upper  portion  of  this  articulation 
is  rough  and  gives  attachment  to  the  posterior 
sacro-iliac  ligament ;  the  lower,  called  the  auric- 
ular surface,  is  smooth  and  covered  with  cartilage. 

THE   PUBES 

Forms  the  anterior  part  of  the  os  innominatum, 
and  the  internal  part  of  acetabulum ;  is  divided 
into  a  body,  an  horizontal  and  descending  ramus. 

Body,  is  the  portion  between  the  rami;  the 
upper  border,  called  the  crest,  terminates  exter- 
nally in  the  spine  and  internally  in  the  angle; 
the  front  surface  is  rough  for  attachment  of  mus- 
cles ;  the  posterior,  smooth,  looks  towards  the  pel- 
vis ;  the  inner  border  forms,  with  its  fellow,  the 
symphysis  pubis.  The  descending  ramus  passes  ob- 
liquely downwards  and  outwards  from  the  body  to 
join  the  ramus  of  the  ischium.  The  horizontal  ra- 
mus passes  outwards  to  form  part  of  the  acetabu- 
lum; its  upper  surface,  triangular,  is  bounded  be- 
hind by  a  ridge,  the  pectineal  line,  which  passes  from 
the  spine  to  form  part  of  the  linea  ilio-pectinea. 

The  obturator  groove'  for  the  obturator  vessels 
and  nerve,  is  situated  upon  the  under  surface  of 
the  horizontal  ramus. 

The  obturator  or   thyroid  foramen  is    the  oval 


22 

opening  bounded  above  by  the  pubes,  below  by 
the  ischium. 

THE  ISCHIUM 

Forms  the  lower,  outer,  and  back  part  of  the 
OS  innominatum. 

Bodij,  forms  the  outer  and  back  part  of  the 
acetabulum  ;  immediately  below  this  cavity  is  a 
transverse  groove  for  the  tendon  of  the  obturator 
externus  muscle.  The  anterior  free  border  of  the 
body  assists  to  form  the  obturator  foramen,  the 
posterior  to  form  the  lesser  sciatic  notch. 

Spine,  projects  from  posterior  part  of  body, 
and  gives  attachment  to  the  lesser  sacro-sciatic 
ligament. 

Tuberosity,  the  thickest  part  of  the  bone,  on 
which  the  body  rests  when  sitting,  gives  attach- 
ment to  the  greater  sacro-sciatic  ligament.  Be- 
tween this  process  and  the  spine  is  a  shallow  groove 
for  the  tendon  of  the  obturator  internus  muscle. 

Ascending  ramus,  turns  upwards,  forwards,  and 
inwards,  and  joins  the  descending  ramus  of  the 
pubes;  it  bounds  the  obturator  foramen  by  its 
thin  border,  and  the  lower  opening  of  the  pelvis 
by  its  thick  one. 

THE   ACETABULUM 

Is  a  cup-shaped  cavity  on  the  outer  aspect  of 
the  bone;  is  formed  by  the  junction  of  the  ilium, 


23 

iscliium,  and  pubes — the  ilium  forming  rather  less 
than  two-fifths,  the  ischium  rather  more  than  two- 
fifths,  and  the  pubes  the  remaining  fifth.  It  is 
bounded  by  a  broad  articular  rim  for  the  head  of 
the  femur,  below  a  depression  for  a  mass  of  fat, 
containing  blood-vessels  for  the  supply  of  the  syno- 
vial membrane.  It  is  surrounded  in  the  greater 
part  of  its  circumference,  by  a  margin,  which  is 
prominent  at  the  upper  and  lower  part,  but  defi- 
cient at  the  lower  and  inner  part,  towards  the  obtu- 
rator foramen.  The  part  where  the  margin  is  want- 
ing is  called  the  cotyloid  notch,  and  is  bi  idged  over 
by  the  transverse  ligament ;  to  the  borders  of  the 
notch  is  attached  the  ligamentum  teres. 

Differences  between  the  male  and  female  pelvis: 
The  male  pelvis  is  heavier,  the  iliac  crests  less 
expanded,  the  depressions  for  muscles  better 
marked,  the  obturator  foramen  larger,  the  inlet  and 
outlet  of  the  pelvis  sijiallcr,  tha  pubic  arch  more 
pointed,  the  tuberosities  of  the  ischia  and  acetabula 
less  wide  apart,  the  sacrum  narrower  and  more 
curved,  and  the  coccyx  more  fixed. 

The  pelvis  is  divided  by  the  linea  ilia  pectinea 
into  the  false  and  true  pelvis.  The  false  is  that 
part  above  the  line,  the  true  that  below  it.  The 
upper  part  of  the  true  pelvis  is  called  the  hrim  or 
inlety  and  has  three  principal  diameters,  antero- 
posterior, transverse,  and  oblique.  Of  these  the 
transverse  is  the  longest,  its  average  being  five 


24 

inches.  The  lower  part  of  the  true  pelvis  is 
termed  the  outlet,  and  has  two  diameters,  the 
antero-posterior  and  transverse.  The  former  ex- 
tends from  the  coccyx  to  the  symphysis  pubis,  the 
latter  between  the  two  ischiadic  tuberosities. 

The  average  diameter  of  these  is  four  inches. 

Development. — By  eight  centres — three  primary 
(one  each  for  the  ilium,  ischium,  and  pubes)  and 
five  secondary  ones  (one  each  for  tlie  crest  of  the 
ilium,  the  symphysis  pubis,  the  tuberosity  of  the 
ischium,  the  anterior  superior  spine  of  the  ilium, 
and  the  bottom  of  the  acetabulum). 

THE     UPPER     EXTREMITY 

Consists  of  the  shoulder,  the  arm,  forearm  and 
hand. 

THE    BONES    OF    THE    SHOULDER    ^ 

Are  the  clavicle  and  the  scapula. 

THE     CLAVICLE 

Is  placed  horizontally  between  the  sternum  and 
the  acromion  process  of  the  scapula,  and  is  curved 
like  the  italic/. 

Sternal  end,  thick,  presenting  a  concavo-convex, 
triangukir,  articular  surface ;  its  edge  is  rough 
for  ligaments. 

Bodt/,  cylindrical  towards  sternum,  flat  and  ex- 


25 

paneled  towards  its  acromial  end.  In  front  its 
inner  curve  is  convex,  its  outer  curve  concave. 
Upon  its  under  surface  are,  1,  towards  the  sternal 
extremity  a  rough  surface  for  the  costo -clavicular 
ligament ;  2,  towards  the  acromial  extremity,  a 
rougli  oblique  line  for  the  coraco-clavicular  liga- 
ments, and  between  both  a  groove  for  the  sub- 
clavius  muscle,  in  which  groove  is  situated  the 
nutrient  foramen. 

Acromial  cud,  rough  and  flattened,  passes  over 
the  coracoid  process  to  join  the  acromion,  with 
which  it  articulates  by  a  small  oval  flattened  sur- 
face. 

Development. — By  two  centres,  one  for  the  shaft 
and  one  for  the  sternal  end. 


THE  SCAPULA, 

Situated  on  the  upper  and  back  part  of  the 
thorax,  extending  from  the  second  to  the  seventh 
ribs,  inclusive. 

It  is  triangular  in  shape,  and  has  two  surfaces, 
three  borders,  and  three  augles. 

Costce  or  borders. — The  superior  or  cervical  is 
the  shortest  and  presents  on  its  extremity  a  notch 
for  the  supra-scapular  nerve ;  the  external  or  axil- 
lary border  next  in  size  is  the  thickest,  and  has  a 
rough  ridge  for  the  triceps  muscle  ;  below  this  is 
a  groove  for   the   dorsalis   scapulae   artery;   the 


26 

posterior  or  vertebral  is  the  longest,  and  is  also 
called  the  base  of  the  scapula. 

Angles. — The  superior  angle  is  acute  and  prom- 
inent, the  inferior  is  rounded  and  thicker,  and  the 
anterior  is  the  thickest  and  forms  the  glenoid  cav- 
ity, which  is  connected  to  the  body  by  a  thin  pro- 
cess, the  neck. 

Anterior  surface  or  ventor  or  subscapular  fossa, 
is  slightly  concave  and  divided  by  three  or  four 
lines  which  run  from  above  obliquely  downwards 
and  inwards. 

Posterior  or  dorsal  surface,  is  divided  by  the 
spine  into  two  unequal  fossae — the  upper,  the  small- 
er, tlie  supra-spinous  ;  the  lower,  the  infra-spinous 
fossa. 

Spine,  arises  by  a  small  triangular,  flat  surface 
at  the  vertebral  border  and  passes  forward,  becom- 
ing more  prominent  and  terminates  in  the  acro- 
mion, which  surmounts  the  shoulder-joint  and  ar- 
ticulates with  the  acromial  end  of  the  clavicle  by 
a  small  oval  surface. 

Supraspinous  fossa,  situated  above  the  spine,  is 
deep,  and  presents  a  nutrient  foramen  ;  it  gives 
origin  to  the  supra-spinatus  muscle. 

Infra-spinous  fossa,  larger,  irregularly  concave- 
convex,  gives  origin  to  the  infra-spinatus  muscle, 
the  teres  minor  muscle,  and  by  an  inferior  rough 
surface  to  the  teres  major  muscle, 

Coracoid  process,  overhangs  the  inner  and  upper 


27 

part  of  the  glenoid  cavity.  This  process  has  a 
crooked  direction,  and  gives  origin  to  the  common 
tendon  of  the  coraco-hrachialis  and  biceps ;  to  the 
insertion  of  the  pectoralis  minor,  and  attachment 
to  ligaments. 

Glenoid  cavity,  articulates  with  the  h3ad  of  the 
humerus,  is  pyriform  and  shallow,  broader  below, 
and  affords  origin  at  its  upper  narrow  part  to  the 
long  head  of  the  biceps. 

Neck,  is  the  contracted  portion  of  the  scapula 
behind  the  glenoid  cavity  ;  it  affords  attachment 
to  the  glenoid  ligament. 

Development, — By  seven  centres — one  for  the 
body,  two  each  for  the  coracoid  and  acromial  pro- 
cesses, one  for  the  posterior  border,  and  one  for 
the  inferior  angle. 

THE   HUMERUS, 

Articulates  with  the  scapula  above,  and  ulna 
and  radius  below  ;  it  is  divisible  into  a  shaft  and 
two  extremities. 

Head,  forms  about  -^  of  a  sphere,  is  smooth,  and 
covered  with  cartilage  in  the  recent  state.  Its 
direction  is  obliquely  backwards,  upwards  and  in- 
wards to  the  glenoid  cavity  of  the  scapula. 

Neck,  is  the  slightly  constricted  base  of  the  head 
for  the  attachment  of  the  capsular  ligament.  It  is 
united  to  the  shaft  at  an  obtuse  angle. 

Two  tuberosities  are   situated  at  the  top  of  the 


28 

shaft.  They  are  separated  by  a  groove,  the  bici- 
pital. The  greater  is  external,  and  affords  inser- 
tions by  three  flat  surfaces  to  the  supra-spinatus, 
infra-spinatus,  and  teres  minor  muscles ;  the  lesser 
is  more  internal  and  gives  insertion  to  the  sub- 
scapularis  muscle. 

Bicipital  groove,  is  situated  between  the  tubero- 
sities, lodges  the  long  tendon  of  the  biceps,  and 
gives  insertion  by  anterior  margin  to  the  pectoralis 
major  and  by  its  posterior  margin  to  the  latissi- 
mus  dorsi  and  teres  major  muscles. 

Shaft,  is  rather  twisted,  the  upper  extremity 
cylindrical,  the  lower  flattened ;  two  longitudinal 
ridges,  arising  one  from  the  outer  the  other  from 
the  inner  condyle,  afibrd  attachment  to  intermus- 
cular septa,  and  divide  the  bone  into  an  anterior 
and  posterior  surface.  The  outer  condyloid  ridge 
is  interrupted  by  an  oblique  groove  which  lodges 
the  musculo-spiral  nerve  and  superior  profunda 
artery;  upon  the  external  and  central  aspect  is  a 
triangular  rough  surface  for  insertion  of  the  del- 
toid muscle,  and  upon  the  inner  side  of  the  centre 
is  a  rough  line  for  the  insertion  of  the  coraco-bra- 
chialis  musc!e.  The  posterior  surface  gives  origin 
to  second  and  third  heads  of  the  triceps.  The  nu- 
trient foramen  is  directed  towards  the  joint. 

Internal  condyle  is  prominent  and  sharp,  aflbrd- 
ing  attachment  to  the  pronator  radii  teres  and 
flexor  muscles  and  the  internal  lateral  ligament. 


^ 


S9 


External  condyle,  less  prominent,  but  descends 
nearer  to  the  joint,  gives  origin  to  the  anconeus, 
the  extensor  muscles,  to  the  supinator  brevis,  and 
to  the  external  lateral  ligament. 

The  inferior  aHiculating  surface  presents  exter- 
nally a  small  round  head  or  capitellum,  situated 
nearer  the  anterior  than  the  posterior  part  of  the 
bone,  for  the  radius.  Internally  the  trochlea  or 
pulley-like  surface*  for  the  ulna,  which  extends 
round  to  the  posterior  aspect  of  the  bone. 

Coronoid  fossa,  in  front  of  the  bone  above  the 
trochlea,  and  receives  the  coronoid  process  of  the 
ulna  when  flexed. 

Olecranon  fossa,  at  the  back  of  the  bone  above 
the  trochlea,  and  receives  the  olecranon  process  of 
the  ulna  when  extended. 

Development. — From  seven  centres — one  each 
for  the  head,  greater  tuberosity,  shaft,  external 
condyle,  capitellum,  trochlea,  and  internal  condyle. 


Is  placed  on  the  inner  side  of  the  forearm,  and 
is  longer  and  stronger  than  the  radius. 

Upper  extremity  articulates  with  the  humerus 
and  radius. 

Olecranon  process  forms  the  projection  of  the 
elbow,  is  the  highest  part  of  the  bone,  and  by 
its   upper  surface  gives  insertion   to  the   triceps 


80 


^^ 


muscle  ;  posterior  to  this  it  is  smooth  for  a  bursa 
mucosa. 

Coronoid  process,  anterior  and  inferior  to  the 
olecranon,  is  smaller  than  it,  and  has  below  a  tri- 
angular rough  surface  for  the  insertion  of  the  bra- 
chialis  anticus  muscle  ;  on  the  inner  aspect  there 
are  two  eminences,  one  for  the  second  head  of  the 
pronator  radii  teres,  the  other  for  the  flexor  sub- 
limis  digitorum  ;  to  the  free  border  of  this  process 
is  attached  the  internal  lateral  ligament. 

Grea'er  sigmoid  cavity  has  its  long  axis  from 
before  backwards,  is  divided  in  the  centre  by  a 
ridge  into  two  lateral  portions,  and  receives  the 
trochlea  of  the  humerus.  It  is  bounded  above  by 
the  olecranon,  below  by  the  coronoid  process. 

Lesser  sigmoid  cavity,  on  the  outer  side  of  the 
coronoid  process,  is  concave  and  oval,  and  receives 
the  side  of  the  head  of  the  radius. 

Shaft  presents  three  surfaces  and  three  borders  ; 
the  anterior  surface  gives  origin  above  to  the  flexor 
profundus  digitorum  ;  below  to  the  pronator  quad- 
ratus,  and  is  pierced  by  the  nutrient  foramen  which 
is  directed  upwards  ;  the  posterior  surface  gives  in- 
sertion to  the  anconeus,  and  origin  to  the  supinator 
brevis  and  extensor  muscles  of  the  thumb  and 
index  finger  ;  the  internal  gives  origin  to  the  flexor 
profundus  digitorum;  below  it  is  subcutaneous. 
Of  the  borders,  that  directed  towards  the  radius  is 
the  best  marked  :  it  gives  attachment  to  the  inter- 


81 

osseous  membrane.  The  upper  tlirec-fourths  of 
the  posterior  border  is  well  marked,  and  serves  for 
the  attachment  of  an  aponeurosis  common  to  the 
origins  of  the  flexor  carpi  ulnaris,  extensor  carpi- 
ulnaris,  and  the  flexor  profundus  digitorum. 

Carpal  extremity,  slender  and  rounded,  presents 
the  head,  which  by  its  side  articulates  with  the 
radius,  and  by  its  carpal  aspect  with  the  fibro- 
cartilage  of  the  wrist  joint ;  also  the  styloid  process 
at  its  inner  margin,  which  by  its  apex  gives  at- 
tachment to  the  internal  lateral  ligament  of  the 
carpus,  and  by  a  depression  at  its  root,  to  the  fibro- 
cartilage  ;  posteriorly  it  presents  a  groove  for  the 
tendon  of  the  extensor  carpi  ulnaris  muscle. 

Development. — By  three  centres — one  for  the 
olecranon,  one  for  the  shaft,  and  one  for  the  lower 
extremity. 

THE  RADIUS 

Is  situated  external  to  the  ulna,  and  is  shorter 
than  that  bone  by  the  length  of  the  olecranon. 

Ileadj  a  circular  cavity  with  a  smooth  vertical 
border,  articulates  above  with  the  capitellum  of 
the  humerus,  and  laterally  with  the  lesser  sigmoid 
cavity  of  the  ulna. 

Necky  about  an  inch  in  length,  narrow  and 
rounded,  and  terminating  in  the 

Tubercle,  a  prominent  process,  into  the  posterior 
part  of  which  is  inserted  the  biceps  muscle. 


Shnfi,  triangular  and  somewhat  curved  ;  by  its 
anterior  surface  it  affords  origin  to  the  flexor  longus 
pollicis,  and  insertion  to  the  pronator  quadratus 
muscles  ;  by  its  posterior  convex  surface  to  the 
supinator  radii  brevis  and  extensor  muscles  of  the 
thumb;  its  external  surface  is  round  and  convex, 
and  rough  near  its  centre  for  the  insertion  of  the 
pronator  radii  teres  ;  leading  from  the  tubercle  to  the 
outer  surface  is  an  oblique  ridge  which  gives  origin 
to  the  flexor  sublimis  digitorum.  The  inner  border 
is  sharp  for  the  attachment  of  the  inter-osseous 
membrane,  and  the  foramen  for  the  nutrient  artery 
is  upon  the  anterior  surface  and  directed  upwards. 

Carpal  extremity,  expanded  and  quadrilateral, 
gives  attachment  by  its  anterior  border  to  the 
anterior  carpal  ligament ;  on  its  posterior  aspect  it 
is  marked  by  a  number  of  grooves :  the  most  ex- 
ternal one  lodges  the  extensores  ossis  metacarpi 
pollicis  and  primi  internodii  pollicis  ;  the  second, 
the  extensores  carpi  radialis  longior  and  brevior ; 
the  third,  narrow  and  oblique,  the  extensor  se- 
cundi  internodii  pollicis;  the  fourth,  the  exten- 
sor communis  digitorum  and  indicator;  and  the 
groove  between  the  radius  and  ulna  gives  passage 
to  the  extensor  minimi  digiti. 

Styloid  process,  prolonged  on  the  outer  side  of 
the  bone  downwards,  gives  attachment  by  its  apex 
to  the  external  lateral  ligament ;  to  its  base  is  in- 
serted the  supinator  radii  longus. 


33 

Sigmoid  cavitij,  on  the  inner  border  of  the  carpal 
extremity  for  articulation  with  the  uhia. 

Carpal  aspect  presents  two  concave,  articular 
facets,  divided  by  a  slight  ridge ;  the  external  being 
triangular  for  articulation  with  the  os  scaphoides, 
the  internal  quadrilateral  for  the  os  lunare. 

Development. — One  for  the  shaft  and  one  for 
each  extremity. 

THE  CARPUS 

Consists  of  two  rows  of  small  bones,  four  bones 
in  each  row,  placed  between  the  forearm  and  meta- 
carpus. It  is  convex  and  rough  upon  its  dorsal 
aspect  and  concave  upon  its  palmar  aspect,  where 
the  vessels,  nerves,  and  tendons  of  the  flexor  mus- 
cles are  situated ;  towards  the  radius  and  inter- 
articular  cartilage  of  the  wrist  it  is  convex ;  to- 
wards the  metacarpus  it  presents  articular  sur- 
faces for  the  metacarpal  bones.  Each  carpal  bone 
has  one  centre  of  ossification. 


FIRST   ROW. 

Os  Scaphoides. 

Situation,  on  outer  and  upper  part  of  the  car- 
pus, next  the  styloid  process  of  the  radius. 

Articulations y  with  the  radius  above,  with  the 
trapezium  and  trapezoides  below,  and  with  the 
lunure  and  magnum  internally. 


34 

Os  Lunare. 

Situation,  between  the  scaphoides  and  cunei- 
forme.  The  surface  which  articulates  with  the 
first  metacarpal  bone  is  concave  in  one  direction, 
convex  in  the  other. 

Os  Trapezoides, 

Situation,  between  the  trapezium,  magnum,  sca- 
phoides, and  metacarpal  bone  of  the  index  finger. 

Articulations,  with  the  scaphoides  above,  the 
trapezium  externally,  the  magnum  internally,  and 
below  with  the  metacarpal  bone  of  the  index  finger. 

Os  Magnum. 

Processes,  head,  neck,  and  body. 

Situation,  between  the  scaphoides  and  lunare, 
and  the  second,  third,  and  fourth  metacarpal  bones. 

Articulations,  by  its  head  with  the  scaphoides 
and  lunare,  by  its  base  with  the  s^econd,  third,  and 
fourth  metacarpal  bones  ;  externally  with  the  tra- 
pezoides, and  internally  with  the  unciforme. 

Os  Unciforme. 

Situation,  between  the  cuneiforme  and  metacar- 
pal bones  of  the  ring  and  little  fingers. 

Articulations,  with  the  lunare  above,  the  magnum 
externally,  the  cuneiforme  internally,  and  below 
with  the  fourth  and  fifth  metacarpal  bones. 


35 

Process,  a  hook-like  process  upon  its  palmar 
aspect. 

THE   FINGERS. 

The  fingers  are  composed  of  three  phalanges, 
except  the  thumb,  which  has  only  two. 

The  first  phalanges  are  five  in  number,  their 
bases  presenting  oval  concavities  for  the  heads  of 
the  metacarpal  bones ;  their  anterior  extremities 
are  convex  from  before  backwards,  and  concave 
from  side  to  side,  to  articulate  with  the  second 
phalanges. 

The  middle^  or  second  phalanges,  are  four  in 
number,  and  smaller  than  the  first;  their  bases 
present  pully-like  surfaces,  to  form  a  ginglymoid 
joint  with  the  first  phalanges,  and  at  their  anterior 
extremities  resemble  the  first. 

The  ungual,  or  third  phalanges,  are  five  in  num- 
ber, and  the  smallest.  By  their  bases  they  form 
a  ginglymoid  joint  with  the  middle  phalanges  ; 
and  their  extremities  are  convex  upon  their  dorsal 
aspects  for  the  support  of  tbe  nail,  whilst  their 
palmar  aspects  are  irregularly  tuberculated  for  the 
extremities  of  the  fingers. 

The  sesamoid  hones  are  sometimes  absent.  In 
general  two  are  to  be  found  between  the  metacarpal 
bone  of  the  thumb  and  its  first  phalanx,  and  one 
or  two  at  the  corresponding  joint  of  the  index 
finger.  ' 

d3 


36 

Each  phalanx  has  two  centres  of  ossification, 
one  for  the  base,  and  one  for  the  shaft. 

THE    LOWER   EXTREMITY. 

The  bones  proper  to  the  lower  extremity  are 
the  femur,  the  tibia,  the  fibula,  the  patella,  seven 
tarsal  bones,  five  metatarsal  bones,  and  fourteen 
phalanges. 

FEMUR. 

*  Head,  forms  nearly  two-thirds  of  a  sphere,  and 
articulates  with  the  acetabulum,  being  directed 
forwards,  upwards,  and  inwards ;  below  and  behind 
its  centre  is  a  rough  depression  for  the  ligamentum 
teres;  its  junction  with  the  neck  is  marked  by  a 
rough  line.  With  the  exception  of  these  parts  the 
head  is  covered  by  cartilage  in  the  recent  state. 

Neck,  extends  obliquely  downwards,  outwards, 
and  forwards,  and  connects  the  head  with  the 
shaft,  which  it  joins  at  an  obtuse  angle;  it  is  flat- 
tened from  before  backwards,  and  its  lower  border 
is  much  longer  than  its  upper.  The  obliquity  of 
the  neck  to  the  shaft  varies  at  different  periods  of 
life,  forming  in  children  a  gentle  curve  from  the 
axis  of  the  shaft,  while  in  old  subjects  the  neck 
forms  nearly  a  right  angle  with  the  shaft. 

Great  trochanter,  is  continued  upwards  from  the 
shaft,  but  does  not  extend  as  high  as  the  head ;  is 
situated  externally,  and  gives  attachment  to  the 


37 

gluteus  mcdius,  gluteus  minimus,  pyriformis, 
obturator  internus  and  two  gemelli,  quadratus 
femoris,  and  part  of  the  vastus  cxternus.  Over  its 
outer  surface  plays  the  flat  tendon  of  the  gluteus 
maximus. 

Dujltal,  or  trochanteric  fossa,  is  situated  at  the  root 
of  the  great  trochanter,  and  affords  insertion  to 
the  obturator  externus. 

Lesser  trochanter,  is  placed  posterior  and  internal 
to  the  shaft,  and  has  inserted  into  it  the  tendon  of 
the  psoas  magnus,  and  the  surface  immediately 
below  affords  insertion  to  the  iliacus  muscle.  Be- 
tween the  tendon  and  the  bone  is  a  bursa. 

Inter-trochanteric  lines,  are  two  in  number,  one 
anterior,  and  the  other  posterior,  the  latter  being 
the  more  prominent ;  as  their  name  implies,  they 
pass  obliquely  from  one  trochanter  to  the  other. 

Shaft,  is  broad  at  each  extremity,  particularly 
towards  the  knee,  and  is  narrow  and  triangular  in 
the  centre;  it  is  arched  and  smooth  anteriorly, 
where  it  gives  origin  to  the  crureus  and  subcru- 
reus  muscles ;  the  posterior  aspect  is  concave,  and 
presents  a  prominent  ridge  called  the  linea  aspera. 
The  foramen  for  the  nutrient  artery  is  situated  on 
this  aspect  about  the  middle  of  the  bone,  and  is 
directed  upwards. 

Linea  aspera,  for  the  attachment  of  muscles,  is 
a  prominent  ridge,  extending  along  the  central 
third  of  the  back  of  the  shaft ;  towards  the  up- 


ae 

per  third  it  bifurcates,  one  ridge  running  towards 
each  trochanter;  inferiorly  it  also  divides  into  two 
ridges,  which  pass  to  each  condyle,  the  inner  one 
being  interrupted  where  the  popliteal  vessels  pass 
over  it.  Between  these  inferior  ridges  there  is  a 
flat,  triangular  surface,  which  forms  part  of  the 
popliteal  space. 

-External  condijle,  projects  more  upon  the  ante- 
rior surface  of  the  femur  than  the  internal;  its 
articular  surface  is  broader  and  ascends  higher 
upon  the  shaft ;  upon  its  outer  surface  it  presents 
a  narrow  groove  for  the  origin  of  the  popliteus  :  to 
the  posterior  part  of  the  inner  surface  is  attached 
the  anterior  crucial  ligament. 

Interned  condtjle,  more  prominent,  longer,  and 
narrower  than  the  external ;  and  it  descends  lower 
in  order  that  both  condyles  should  rest  upon  the 
tibia  in  the  natural  oblique  direction  of  the  femur. 
It  presents  on  its  inner  side,  and  behind  a  depres- 
sion for  the  gastrocnemius  :  the  outer  side  gives  at- 
tachment anteriorly  to  the  posterior  crucial  liga- 
ment. 

External  tuberosity,  above  the  external  condyle, 
for  the  attachment  of  the  external  lateral  ligament 
of  the  knee-joint. 

Internal  tuberosity,  above  the  external  condyle, 
and  more  prominent  than  the  external,  for  the  in- 
ternal lateral  ligaments  and  the  insertion  of  the 
adductor  magnus  tendon. 


39 

Trochlea,  between  the  condyles  on  their  anterior 
aspect,  supports  the  patella  when  the  leg  is  ex- 
tended. 

Inter-condijloid  notch,  is  situated  posteriorly  be- 
tween the  condyles. 

Development. — By  five  centres  ;  one  for  shaft 
and  neck,  one  for  each  extremity,  and  one  for  each 
trochanter. 

PATELLA, 

Is  a  sesamoid  bone,  triangular,  the  base  superi- 
orly having  the  common  extensor  tendon  inserted 
into  it,  the  apex  below,  to  which  is  attached  the 
ligamcntum  patellae. 

Anterior  surface,  is  convex,  and  presents  a 
fibrous  appearance. 

Posterior  surface,  presents  two  articular  sur- 
faces, divided  by  a  prominent  ridge ;  the  internal 
surface  is  the  deeper,  while  the  external  is  broad, 
and  shallow.  The  inner  border  is  sharper  and 
more  prominent  than  the  outer. 

Development. — By  one  centre. 


Upper  extremity,  articulates  with  the  femur,  and 
is  expanded  from  side  to  side  to  form  two  articular 
surfaces  which  support  the  condyles  of  the  femur. 
These  surfaces  are  oval  and  concave,  ot  which  the 
inner  is  the  deeper  and  longer.      Between  them 


40 

is  the  spine,  a  bifid  extremity,  in  front  of  and 
behind  which  are  depressions  for  the  attachment 
of  the  crucial  ligaments  and  the  semilunar  carti- 
lages. On  each  side  of  the  upper  extremity  is  a 
rounded  prominence,  the  external  and  internal 
tuberosities.  On  the  outer  one  is  a  flat  articular 
surface  for  the  fibula,  on  the  inner  a  groove  for  the 
insertion  of  the  semi-membranosus  muscle.  An- 
teriorly it  is  convex  and  has  a  tubercle  for  the  at- 
tachment of  the  ligamentum  patellce ;  posteriorly 
it  is  slightly  hollowed. 

Shajl,  triangular,  presenting  three  surfaces  sep- 
arated by  corresponding  borders.  The  inner  sur- 
face is  convex  and  subcutaneous,  except  at  its 
upper  part,  where  the  tendons  of  the  sartorius, 
gracilis,  and  semi-tendinosus  pass  over  it ;  it  ter- 
minates below  in  the  inner  malleolus ;  the  outer 
surface  is  covered  by  the  tibialis  an  tic  us  muscle  for 
its  upper  two-thirds  and  is  here  concave  ;  interiorly 
the  bone  is  flattened  to  support  tlie  tendons  of  the 
extensor  tendons  of  the  toes  ;  the  posterior  surface 
presents  an  oblique  ridge  directed  upwards  and 
outwards  for  the  origin  of  the  soleus,  above  this  a 
triangular  flat  surface  for  the  insertion  of  thepopli- 
teus,  and  below  the  ridge  the  bone  gives  origin  to 
the  flexor  longus  digitorum,  and  the  tibialis  pos- 
ticus ;  the  nutrient  foramen,  which  is  the  largest  in 
the  body,  is  a  little  below  this  ridge,  and  directed 
downwards.     Of  the  borders  the  anterior  is  most 


41 

prominent  and  subcutaneous  ;  the  inner  is  less  de- 
fined, and  the  outer  is  well  marked,  giving  attach- 
ment to  the  interosseous  membrane. 

Lower  extremity,  is  much  smaller  than  the 
upper  and  quadrilateral,  the  anterior  edge  being 
convex  for  the  passage  of  the  extensor  tendons  ; 
the  posterior,  marked  by  a  groove,  for  the  passage 
of  the  tendon  of  the  flexor  longus  pollicis  muscle ; 
the  external  presenting  a  rough,  triangular  depres- 
sion for  the  fibula,  and  the  internal  terminating  in 
the  internal  malleolus. 

Internal  malleolus,  is  convex  and  subcutaneous 
internally  ;  its  articular  aspect  is  smooth  to  articu- 
late with  the  astragalus;  it  gives  attachment  by- 
its  inferior  border  to  the  internal  lateral  ligament 
of  the  ankle-joint,  and  is  grooved  posteriorly  for 
the  tendons  of  the  tibialis  posticus  and  the  flexor 
longus  digitorum  muscles. 

Inferior  articular  surface,  rests  upon  the  upper 
surface  of  the  astragalus ;  it  is  quadrilateral  and 
concave  from  before  backwards,  and  joins  the 
smaller  articular  surface  of  the  internal  malleolus 
at  a  right  angle. 

Development. — By  three  centres,  one  for  the  shaft 
and  one  for  each  extremity. 

FIBULA. 

Situation,  on  the  outer  side  of  the  tibia. 


42 

Upper  extremity,  or  head,  articulates  with  the 
tibia  by  a  small  circular  surface  directed  upwards 
and  inwards,  and  affords  attachment  to  the  ex- 
ternal lateral  ligament  of  the  knee-joint  and  the 
biceps  muscle  by  a  single  projection,  called  the 
styloid  process. 

Neck,  is  the  small  constricted  part  by  which  the 
head  is  united  to  the  shaft. 

Shaft,  triangular  and  twisted,  gives  origin  to  the 
peronei  muscles  by  its  external  surface  to  the 
soleus,  tibialis  posticus,  and  flexor  lougus  pollicis 
by  its  posterior  surface,  to  the  extensor  longus 
digitorum,  peroneus  tertius,  and  extensor  proprius 
pollicis  by  its  anterior  surface.  Its  inner  edge  is 
well  defined,  to  afford  attachment  to  the  interos- 
seous membrane ;  and  the  nutrient  foramen,  di- 
rected downwards,  is  placed  upon  the  posterior 
aspect  of  the  bone. 

Tarsal  extremity,  presents  a  large  oval  process 
called  the  external  malleolus,  about  two  inches 
and  a  half  above  which  the  shaft  is  constricted. 

External  malleolus,  is  larger,  longer,  and  more 
prominent  than  the  internal,  on  a  line  posterior  to 
which  it  is  situated  ;  by  its  edge  it  afibrds  attach- 
ments to  the  external  lateral  ligament  of  the  ankle- 
joint.  Its  outer  surface  is  convex  and  subcuta- 
neous ;  the  inner  or  articular  is  triangular  and 
smooth  to  articulate  with  the  outer  side  of  the  as- 
tragalus, to  the  side  of  which  is  a  rough  depres- 


I 


43 

sion ;  the  posterior  border  presents  a  groove  for 
the  passage  of  the  tendons  of  the  peronei  muscles. 
Development. — By  three  centres,  one  for  the  shaft 
and  one  for  each  extremity. 

THE    TARSUS, 

Forms  the  posterior  part  of  the  foot ;  the  bones 
which  compose  it  are  seven  in  number,  and  articu- 
late with  one  another.  It  is  connected  above  to 
the  tibia  and  fibula,  below  it  is  arched,  and  ante- 
riorly it  articulates  with  the  bases  of  the  five 
metatarsal  bones.  The  seven  tarsal  bones  are  the 
calcuneum,  astragalus,  scaphoid,  cuboid,  and  three 
cuneiform  bones. 

CALCANEUM,    OR    OS    CALCIS. 

Situation,  at  the  posterior  and  under  part  of  the 
tarsus. 

Posterior  aspect,  elongated  to  form  the  heel, 
presents  a  smooth  surface  above  for  a  bursa,  and  a 
rough  surface  below  for  the  insertion  of  the  tendo- 
Achillis,  and  plantaris. 

Anterior  aspect,  articulates  by  a  triangular  con- 
cavo-convex surface  with  the  cuboid  bone. 

Superior  aspect,  presents  two  articular  facets  to 
support  the  astragalus  :  the  posterior  convex ;  the 
anterior,  oblong  and  concave,  is  situated  on  the 
upper  aspect  of  the  sustentaculum  tali.     They  are 


44 

separated  by  a  long  groove  for  the  attachment 
of  the  interosseous  Hganient. 

Inferior  aspect,  is  irregular,  and  presents  two 
tubercles,  the  internal  of  which  is  the  more  promi- 
nent ;  they  afford  origin  to  muscles. 

External  aspect,  presents  posteriorly  a  small 
tubercle  for  the  attachment  of  the  middle  fascicu- 
lus of  the  external  lateral  ligament.  In  front  is  a 
ridge,  the  peroneal  tubercle,  above  which  passes 
the  peroneus  brevis  and  below  the  peroneus  longus. 

Internal  aspect ,  is  deeply  concave  for  the  lodg- 
ment of  the  plantar  vessels  and  nerves  and  the 
flexor  tendons  ;  bounding  the  concavity  above  is  a 
process  of  bone,  the  lesser  process,  or  sustentacu- 
lum tali,  to  the  border  of  which  is  attached  the 
internal  lateral  ligament. 

It  articulates  with  two  bones,  the  astragalus  and 
the  cuboid. 

ASTRAGALUS. 

Situation,  at  the  upper  and  middle  part  of  the 
tarsus,  between  the  malleoli ;  the  tibia  above  and 
the  OS  calcis  below. 

Superior  aspect,  presents  a  smooth  articular  sur- 
face, convex  from  before  backwards,  broader  in 
front  than  behind,  and  articulates  with  the  tibia. 

Inferior  aspect,  presents  two  articular  surfaces 
for  the  OS  calcis,  which  are  separated  by  a  groove 
for  the  interosseous  ligament. 


45 

Posterior  aspect,  is  narrow,  and  presents  a  groove 
for  the  flexor  longus  pollicis,  and  a  pointed  emi- 
nence for  the  posterior  fasciculus  of  the  external 
lateral  ligament. 

Anterior  aspect,  convex  and  smooth,  forms  the 
head,  which  is  directed  forwards  and  inwards,  and 
is  larger  than  the  concavity  of  the  scaphoid  bone, 
with  which  it  articulates.  Between  the  head  and 
the  bone  is  a  narrow  constriction — the  neck. 

External  aspect,  presents  a  triangular  concave 
surface  for  articulation  with  the  external  malleolus. 

Internal  aspect,  presents  a  pyriform  surface  for 
articulation  with  the  internal  malleolus. 

It  articulates  with  the  tibia,  fibula,  os  calcis,  and 
scaphoid. 

SCAPHOIDES. 

Situation,  middle  of  the  tarsus. 

Superior  and  inferior  aspects,  rough,  for  the  at- 
tachment of  ligaments. 

External  and  internal  aspects,  for  the  attachment 
of  ligaments;  the  internal  also  presents  atubeixle 
for  the  insertion  of  the  tendon  of  the  tibialis  pos-  • 
ticus. 

Posterior  aspect,  is  smooth  and  concave,  broader 
externally,  for  articulation  with  the  head  of  tlie 
astragalus. 

Anterior  aspect,  presents  two  vertical  lines,  which 
divide  it  into  three  smooth  surfaces  for  articulation 


46 

with  the  cuneiform  bones,  and  in  general  a  small 
articular  facet  externally,  for  articulation  with 
the  cuboid  bone. 

It  articulates  with  the  astragalus,  three  cunei- 
form bones,  and  occasionally  with  the  cuboid  bone. 

CUBOIDES. 

Situation,  outer  and  anterior  part  of  the  tarsus. 

Superior  aspect,  flat  and  rough,  for  attachment 
of  ligaments. 

Inferior  aspect,  tuberculated  behind  for  the  cal- 
caneo-cuboid  ligament,  and  presenting  a  groove 
anteriorly  for  the  tendon  of  the  peroneus  longus 
muscle. 

Posterior  aspect,  smooth,  concave  and  triangular, 
to  articulate  with  the  os  calcis. 

Anterior  aspect,  presents  two  articular  facets ; 
the  external,  triangular,  articulates  with  the  fifth 
metatarsal  bone;  the  internal,  quadrilateral,  for 
the  fourth  metatarsal  bone. 

External  aspect,  free,  and  is  marked  by  the  com- 
mencement of  the  peroneal  groove. 

Internal  surface  presents  anteriorly  an  oval  facet 
for  articulation  with  the  external  cuneiform  bone, 
and  occasionally  posteriorly  one  for  the  scaphoid 
bone. 

It  articulates  with  os  calcis,  external  cuneiform 
bone,  fourth  and  fifth  metatarsal  bones,  and  occa- 
sionally with  the  scaphoid. 


47 

INTERNAL    CUNEIFORM   BONE, 

The  largest  of  the  three,  articulates  behind  with 
the  scaphoid ;  in  front  with  the  first  metatarsal 
bone ;  externally  with  the  middle  cuneiform  and 
side  of  the  second  metatarsal  bone  ;  on  the  internal 
aspect  there  is  a  smooth  surface  for  the  play  of  the 
tendon  of  the  tibialis  anticus  muscle. 

Tubercle,  is  situated  inferiorly  for  the  insertion 
of  the  tendon  of  the  tibialis  anticus  muscle,  and 
part  of  the  tendon  of  the  tibialis  posticus.  It  arti- 
culates with  the  scaphoid,  middle  cuneiform  and 
first  and  second  metatarsal  bones. 

MIDDLE    CUNEIFORM    BONE, 

The  smallest,  articulates  behind  with  the  sca- 
phoid ;  in  front  with  the  second  metatarsal  bone; 
internally  with  the  internal  cuneiform  and  exter- 
nally with  the  external  cuneiform. 

EXTERNAL    CUNEIFORM    BONE, 

Articulates  behind  with  the  scaphoid  ;  in  front 
with  the  third  metatarsal  bone  ;  internally  with 
the  middle  cuneiform  and  side  of  the  second  meta- 
tarsal bone ;  and  externally  with  the  cuboid  and 
fourth  metatarsal  bone. 

Each  tarsal  bone  has  one  centre  of  ossification, 
except  the  os  calcis,  which  has  two. 


48 

THE    METATAESUS, 

Is  the  middle  part  of  the  foot,  and  is  composed  of 
five  long  bones  placed  between  the  tarsus  and  the 
toes. 

FIRST   METATARSAL   BONE, 

The  shortest  and  thickest,  is  convex  above  and 
concave  below. 

Posterior  extremity,  is  smooth  and  kidney- 
shaped  to  articulate  with  the  internal  cuneiform 
bone. 

Anterior  extremitijj  round,  to  articulate  with  the 
first  phalanx  of  the  great  toe.  The  under  surface 
of  this  extremity  articulates  with  two  sesamoid 
bones,  and  receives  the  insertion  of  the  tendon  of 
the  peroneus  longus. 

SECOND   METATARSAL  BONE, 

The  longest. 

Posterior  extremity,  articulates  with  the  three 
cuneiform  bones,  and  also  with  the  metatarsal  bone. 

Anterior  extremity^  presents  a  round  head,  for 
articulation  with  the  second  toe ;  it  is  separated 
from  the  shaft  of  the  bone  by  a  groove. 

THIRD    METATARSAL   BONE. 

Posterior  extremity,  articulates  with  the  third 
cuneiform  bone. 


49 

Anterior  extremity,  resembles  the  second,  and 
articulates  with  the  third  toe. 

FOURTH    METATARSAL   BONE. 

Posterior  extremity,  articulates  with  the  cuboid 
bone,  and  by  its  inner  side  with  the  third  cunei- 
form. 

Anterior  extremity,  resembles  the  second,  and 
articulates  with  the  fourth  toe. 

FIFTH    METATARSAL   BONE. 

Posterior  extremity,  articulates  with  the  cuboid 
bone,  by  a  surface  directed  obliquely  upwards  and 
outwards. 

Anterior  extremity,  resembles  the  second,  and 
articulates  with  the  fifth  toe. 

PHALANGES,    OR   TOES, 

Are  composed  of  fourteen  bones,  three  to  each 
toe,  except  the  first,  which  has  only  two. 

FIRST   PHALANGES. 

Shape,  convex  above,  concave  below,  and  the 
longest. 

Anterior  extremities,  convex  from  above   down- 
wards, and  concave  laterally  ;  form  ginglymoid 
articulations  with  the  second  phalanges. 
E 


50 

Posterior  extremities,  are  laro^e,  and  present 
rounded  concavities  for  the  heads  of  the  metatar- 
sal bones. 

SECOND    PHALANGES. 

Anterior  extremities,  resembles  those  of  the  first 
phalanges. 

Posterior  extremities,  concave  from  above  down- 
wards, and  conveiL  transversely,  articulate  with 
the  first  phalanges. 

THIRD   PHALANGES. 

Anterior  extremities,  pyramidal  in  form,  support 
the  nails  on  their  upper  surface,  and  are  rough  on 
the  under  surface. 

Posterior  extremities,  resemble  the  posterior  ex- 
tremities of  the  middle  phalanges. 

SESAMOID  BONES, 

Are  uncertain  in  development ;  two  are  generally 
found  at  the  base  of  the  first  phalanx  of  the  great 
toe  and  one  at  that  of  the  fifth  toe.  They  are  also 
frequently  developed  in  the  tendons  which  cross 
the  sole  of  the  foot  in  those  situations  where  they 
are  subjected  to  much  pressure. 


51 

THE  SKULL 

Consists  of  two  parts,  the  cranium  and  the  face : 
the  former  is  comporcd  of  eight  bones,  the  oc- 
cipital, two  parietal,  frontal,  ethmoid,  sphenoid, 
and  two  temporal  ;  the  face,  of  fourteen  bones, 
two  malar,  two  nasal,  two  superior  maxillary,  two 
lachrymal,  two  palate,  two  inferior  turbinated 
bones,  the  vomer  and  the  inferior  maxilla. 

OCCIPITAL   BONE. 

Situation^  posterior  and  inferior  part  of  cranium. 

Posterior  surface^  is  convex,  and  presents  the  ex- 
ternal occipital  protuberance  about  its  centre ;  pass- 
ing from  the  protuberance  to  the  foramen  mag- 
num is  a  ridge,  the  crest  which  affords  attachment 
to  the  ligamentum  nuchae.  Arching  outwards  are 
two  parallel  transverse  hues,  the  superior  and  wfe- 
rior  curved  lines. 

Foramen  magmun,  larger  internally  than  exter- 
nally, is  of  oval  form,  and  transmits  the  me- 
dulla oblongata  and  its  membranes,  the  vertebral 
arteries,  and  spinal  accessory  nerves. 

Condijles,  two  in  number,  smooth,  convex,  and 
oblong,  look  downwards,  outwards  and  back- 
wards ;  they  converge  anteriorly,  and  on  their  in- 
ner aspects  are  two  tubercles  for  the  check  liga- 
ments. 

Anterior  condyloid  foramina,  placed  in  front  of 
E  2 


52 

the  condyles  for  the  passage  of  the  hypoglossal 
nerves :  sometimes  divided  into  two. 

Posterior  condyloid  foramina,  behind  theconclyles 
for  the  passag-e  of  veins  to  the  lateral  sinus.  They 
are  sometimes  absent. 

Jugular  eminences,  external  to  each  condyle; 
each  forms,  with  the  temporal  bone,  the  foramen 
lacerum  posterius. 

Internal  surface,  is  concave,  and  is  divided  into 
four  fossae  by  a  crucial  ridge  ;  the  two  superior  are 
for  the  posterior  cerebral  lobes,  the  two  inferior 
for  the  lobes  of  the  cerebellum.  The  upper  half 
of  the  vertical  line  gives  attachment  to  the  falx 
cerebri,  the  lower  half  to  the  falx  cerebelli ;  the 
transverse  ridge  gives  attachment  to  the  tento- 
rium cerebelli,  and  also  presents  a  groove  for  the 
lateral  sinus.  At  the  junction  of  the  vertical  with 
the  transverse  ridge  is  the  internal  occipital  pro- 
tuberance, where  six  sinuses  meet  at  the  torcular 
Hcrophili — viz.,  the  superior  longitudinal,  the 
straight,  the  two  lateral  and  the  two  occipital. 

Groove  for  the  termination  of  the  lateral  sinus,  on 
each  side  of  the  foramen  magnum  above  the  jug- 
ular eminence. 

Basilar  process,  passes  forwards  and  upwards  to 
join  the  sphenoid  bone,  is  rough  inferiorly  for  the 
attachment  of  the  recti  capitis  antici  major  and  mi- 
nor muscles,  and  the  fibrous  band  of  the  pharynx  ; 
and  upon  its  cerebral  aspect,is  sraoo'.h  and  concave 


53 

from  side  to  side  to  support  tbe  pons  Varolii  and 
basilar  artery,  and  marijed  laterally  by  two  su- 
perficial grooves,  which  lodge  the  inferior  petro- 
sal sinuses.  It  articulates  with  six  bones — viz., 
the  two  parietal,  the  two  temporal,  the  sphenoid, 
and  the  atlas. 

Development. — By  four  centres  ;  one  for  the  ta- 
bular portion  which  is  formed  ni  membrane,  one 
for  the  basilar  process,  and  one  for  each  condyle. 

PARIETAL  BONES. 

Situation,  upper  and  lateral  parts  of  cranium  ; 
they  are  quadrilateral. 

External  surface,  smooth,  convex,  and  marked 
bv  a  semicircular  ridge,  the  temporal  ridge,  which 
is  continuous  wdth  the  temporal  ridge  of  the  frontal 
bone ;  close  to  the  upper  border  is  a  foramen,  the 
parietal  foramen. 

Internal  surface,  concave,  and  marked  by  the 
convolutions  of  the  brain,  and  the  ramifications  of 
the  middle  meningeal  arter}--,  presents  along  its 
upper  border  a  shallow  groove,  which,  with  its  fel- 
low, lodges  the  superior  longitudinal  sinus  ;  exter- 
nal to  this  groove  are  shallow  depressions,  mark- 
ing where  the  Pacchionian  bodies  were  situated. 

Four  horda's. — The  upper  is  the  longest,  and 
joins  its  fellow ;  the  anterior  joins  the  frontal  bone ; 
the  posterior  the  occipital,  and  is  very  irregular; 


54 

and  the  inferior  is  thick  where  it  joins  the  mastoid 
process,  but  thin  and  semicircular  where  it  is  over- 
lapped by  the  squamous  portion  of  tlie  temporal 
bone. 

Four  angles. — The  anterior  inferior  is  long  and 
curved,  and  joins  the  sphenoid  bone ;  upon  its  cere- 
bral aspect  is  a  canal  or  groove  for  the  middle 
meningeal  artery.  The  posterior  inferior  angle  is 
grooved  upon  its  cerebral  aspect  to  lodge  part  of 
the  lateral  sinus.  The  superior  angles  are  rather 
rounded.  Each  parietal  bone  articulates  with  five 
bones — the  occipital,  the  frontal,  its  fellow  of  the 
opposite  side,  the  sphenoid,  and  the  temporal. 

Development. — By  one  centre,  from  membrane. 

TRONTAL   BONE. 

Situation,  upper  and  anterior  part  of  the  skull. 

External,  or  frontal  aspect,  is  smooth,  convex, 
and  arched,  and  presents  a  median  vertical  de- 
pression, which  marks  the  original  division  of  the 
bone  into  two. 

Frontal  eminences,  on  each  side  of  the  median 
line,  marking  the  points  of  ossification  of  the 
bone. 

Superciliary  ridges,  two  prominences  which  ex- 
tend for  about  an  inch  on  each  side  of  the  median 
line,  below  the  frontal  eminences  ;  between  the 
ridges  is  the  glabella,  or  nasal  eminence. 


55 

Misal  spine,  a  projection  at  the  inferior  part  of 
the  median  line. 

Orbital  arches,  form  the  upper  margins  of  the 
orbits,  and  present  towards  their  inner  third  the 
supra-orbital  foramina  or  notches,  for  the  passage 
of  the  supra-orbital  nerve  and  artery. 

External  anrjular  process,  at  the  outer  termina- 
tion of  tlie  orbital  arches. 

Internal  angular  process,  at  the  inner  termination 
of  the  orbital  arches. 

Temporal  ridges,  extend  backwards  and  upwards 
from  the  external  angular  process. 

Internal,  or  cerebral  aspect,  is  concave,  and  pre- 
sents in  the  m.dian  line  a  groove,  which  corre- 
sponds to  the  superior  longitudinal  sinus. 

Crest,  at  the  commencement  of  the  median 
groove,  gives  attachment  to  the  falx  cerebri. 

Foramen  ccecum,  at  the  root  of  the  crest,  gives 
passage  to  a  vein  which  opens  from  the  nose  into 
the  longitudinal  sinus. 

On  each  side  of  the  median  groove  are  depres- 
sions which  correspond  with  the  convolutions  of 
the  brain. 

Horizontal  portion,  or  orbital  processes,  triangular, 
and  form  the  roof  of  the  orbit  by  their  smooth 
concave  surface,  and  on  their  convex  surface  ara 
marked  by  convolutions  of  the  brain.  Towards  the 
external  angular  process  of  each  is  a  fossa  for  the 
lachrymal  gland,  and  at  the  nasal  margin  is  a 


56 

depression  for  the  reflected  tendon  of  tlie  superior 
oblique  muscle. 

Ethmoidal  notch,  quadrilateral,  is  situated  be- 
tween the  orbital  processes,  and  articulates  with 
the  ethmoid  bone  by  a  serrated  margin ;  its  edges 
being  cellular,  to  complete  the  ethmoidal  cells. 

Anterior  and  posterior  ethmoidal  foramina,  along 
the  margin  of  the  ethmoidal  notch,  the  anterior 
giving  passage  to  the  anterior  ethmoidal  vessels 
and  nasal  branch  of  the  ophthalmic  nerve,  the  pos- 
terior one  to  the  posterior  ethmoidal  vessels. 

Frontal  sinuses,  which  exi^t  only  in  the  adult, 
at  the  anterior  inferior  part  of  the  bone  separating 
its  two  tables,  open  on  each  side  of  the  nasal  pro- 
cess. 

It  articulates  with  twelve  bones — viz.,  the  sphe- 
noid, ethmoid,  two  parietal,  two  nasal,  two  supe- 
rior maxillary,  two  lachrymal,  and  two  malar. 

Development. — By  two  centres  in  membrane — 
one  for  each  frontal  eminence. 


TEMPORAL   BONE. 

Situation,  at  the  lateral,  middle,  and  inferior 
part  of  the  skull.  It  is  divided  into  squamous, 
mastoid,  and  petrous  portions. 

Squamous  pojiion,  vertical,  semicircular,  convex, 
and  smooth  on  its  external  aspect;  on  its  internal, 


57 

it  is  marked  by  the  convolutions  of  the  brain,  and 
by  grooves  for  the  middle  meningeal  artery. 

Zijgomatic  process,  arises  by  two  roots  :  one,  an- 
terior, passes  inwards  bounding  the  front  of  the 
glenoid  cavity  ;  the  other,  posterior,  bifurcates,  of 
which  one  division  passes  in  front  of  the  external 
auditory  meatus,  the  other  passes  horizontally  back- 
wards and  is  gradually  lost.  The  process  then 
passes  forwards  and  terminates  in  a  triangular  ser- 
rated border  to  articulate  with  the  malar  bone. 

Zyrjomatic  tubercle,  situated  at  the  junction  of 
the  zygomatic  roots,  and  gives  attachment  to  the 
external  lateral  ligament  of  the  lower  jaw. 

Glenoid  fossa,  transversely  oval,  deep  anteriorly 
for  the  reception  of  the  condyle  of  the  lower  jaw, 
and  shallow  posteriorly,  where  it  lodges  a  portion 
of  the  parotid  gland. 

Glaserian  Jissure,  crosses  the  glenoid  fossa  in  a 
direction  obliquely  forwards  and  inwards.  It  trans- 
mits the  laxator  tympani  muscle,  the  tympanic 
artery,  and  the  processus  gracilis  of  the  malleus. 
The  chorda  tympani  passes  through  a  canal — canal 
of  Iluguicr — which  runs  parallel  to  the  Glaserian 
fissure  and  emerges  close  to  the  Eustacliian  tube. 

Mastoid  process,  at  the  posterior  and  inferior 
aspect  of  the  bone  ;  externally  it  is  rough  for  the 
insertion  of  muscles ;  internally  it  is  grooved  for 
the  lateral  sinus. 

Mastoid  grooves,  internal  to  the  mastoid  process 


58 

for  the  occipital  artery  and  the  origin  of  the  pos- 
terior belly  of  the  digastric  muscle. 

Mastoid  foram£n,  posterior  to  the  mastoid  pro- 
cess for  the  transmission  of  a  vein  to  the  lateral 
sinus. 

Mastoid  cells,  in  the  interior  of  the  mastoid 
process,  and  open  into  the  posterior  part  of  tym- 
panum. 

Petrous  portion,  containing  in  its  interior  the  in- 
ternal ear,  extends  forwards,  inwards,  and  a  little 
downwards,  and  presents  three  surfaces,  three  bor- 
ders, a  base,  and  an  apex. 

Anterior  surface,  presents  for  examination  : 

Depression  for  Gasserian  ganglion  on  the  ante- 
rior extremity. 

Hiatis  Fallopii,  a  foramen  about  the  middle  of 
the  surface,  for  the  passage  of  the  great  petrosal 
nerve.  A  small  opening  external  to  this  for  the 
lesser  petrosal  nerve. 

The  superior  semicircular  canal,  forms  an  emi- 
nence behind  the  hiatus  Fallopii. 

Posterior  surface  presents  for  examination  : 

Meatus  auditorius  internus,  about  its  middle, 
directed  outwards  for  the  transmission  of  the  sev- 
enth pair  of  nerves  and  the  auditory  artery. 

Aqueductus  vestihuli,  a  small  slit-like  opening 
behind  the  internal  meatus,  for  the  passage  of  a 
vein. 

Inferior  surface  presents  for  examination : 


59 

A  rough  surface  for  tlie  origin  of  tensor  tyra- 
pani  and  levator  palati. 

Carotid  canal,  turns  forwards,  upwards,  and  in- 
wards, and  gives  passage  to  the  internal  carotid 
artery  and  sympathetic  plexus. 

Aqueductus  cochlece,  posterior  to  the  styloid  pro- 
cess, for  the  passage  of  a  vein. 

Jugular  fossa,  a  smooth  depression  behind  and  a 
little  external  to  the  carotid  foramen  ;  it  forms 
with  the  occipital  bone,  the  foramen  lacerum  pos- 
terius,  which  transmits  the  internal  jugular  vein 
and  the  eighth  nerves. 

Foramen  for  Arnold's  nerve,  in  the  outer  wall  of 
the  jugular  fossa. 

Foramen  for  Jacobson^s  nerve,  in  the  ridge  of 
bone  between  the  jugular  fossa  and  the  carotid 
foramen,  for  the  transmission  of  Jacobson's  nerve 
to  the  tympanum. 

Styloid  process,  long  and  tapering,  descends 
obliquely  forwards  and  inwards  ;  affords  origin  to 
muscles  and  ligaments. 

Vaginal  process,  a  plate  of  bone  between  the 
carotid  foramen  and  the  mastoid  process. 

Sbjlo-mastoid  foramen,  between  the  styloid  and 
mastoid  processes  for  the  exit  of  the  facial  nerve 
and  the  entrance  of  a  small  artery  ;  near  the  fora- 
men is  a  minute  aperture  for  Arnold's  branch  of 
the  pneumogastric  nerve. 

Auditory  process,  commencing  by  .the  external 


60 

meatus,  leads  inwards  and  forwards  to  the  mem- 
brana  tvmpani,  and  presents  externally  a  rugged 
edge  for  the  attachment  of  the  cartilage  of  iha  ear. 

Meatus  auditorius  externus,  at  the  base  of  the  pe- 
trous portion,  leads  to  the  tympanum. 

The  apex  of  the  petrous  portion  presents  tlie 
termination  of  the  carotid  canal. 

Processus  coddearifonnis,  a  thin  plate  of  bone 
separating  two  canals  which  are  situated  in  the 
angle  between  the  petrous  and  squamous  portions  ; 
the  superior  of  which  transmits  the  tensor  tym- 
pani  muscle;  the  inferior  forming  the  bony  part 
of  the  Eustachian  tube. 

Borders :  the  superior  gives  attachment  to  the 
tentorium  cerebelli,  and  is  grooved  for  the  supe- 
rior petrosal  sinus  ;  the  posterior  presents  in  front 
a  groove  for  the  inferior  petrosal  sinus,  and  be- 
hind the  jugular  fossa ;  the  anterior  has  an  articu- 
lating border  for  the  sphenoid. 

The  temporal  articulates  with  five  bones — the 
occipital,  parietal,  sphenoid,  malar,  and  inferior 
maxilla. 

Development. — By  four  centres,  one  for  the  squa- 
mous, one  for  the  mastoid  and  petrous  portions, 
one  for  the  styloid  process,  and  one  for  the  audi- 
toiy  process. 

SPHENOID   BONE. 

Situation,  wedged  transversely  in  the  base  of 
the  skulL 


61 

Body,  in  the  middle  line,  and  presents  six  sur- 
faces. 

Superior  surface,  presents  a  fossa,  called  sella 
turcica,  i^OY  the  pituitary  body;  in  front  of  this  is  a 
transverse  groove,  the  olivary  process,  on  which 
the  optic  commissure  rests ;  still  more  anteriorly 
is  a  trhingular  process,  the  ethmoidal  spine  ;  be- 
hind the  pituitary  fossa  are  two  rounded  emi- 
nences, the  posterior  clinoid  processes,  below  which 
are  two  notches  for  the  passage  of  the  sixth 
nerve. 

Posterior  surface,  is  rough,  for  connexion  with 
the  basilar  process  of  the  occipital  bone. 

Anterior  surface,  presents  the  openings  of  the 
sphenoidal  sinuses. 

Inferior  surface,  presents  the  rostrum,  which  ar- 
ticulates with  the  vomer. 

Lateral  surfaces,  join  the  great  alae,  and  are 
grooved  for  the  internal  carotid  artery. 

Great  wings,  extend  laterally  from  the  sides  of 
the  body;  each  presents  three  aspects  :  an  anterior, 
smooth  and  quadrilateral,  to  assist  in  forming  the 
outer  wall  of  the  orbit ;  the  second,  superior,  con- 
cave, and  marked  by  cerebral  convolutions,  to  as- 
sist in  forming  the  middle  cranial  fossa;  the  third, 
external,  is  divided  by  a  crest.  The  portion  above 
forms  part  of  the  temporal  fossa,  and  the  portion 
below  part  of  the  zygomatic  fossa. 

Spinous  processes,  extend  backwards  and  out- 


62 

wards,  and  form  the  posterior  termination  of  each 
great  wing. 

Foramina  rotunda,  at  the  internal  part  of  the 
great  wing,  gives  passage  to  the  second  division  of 
the  fifth. 

Foramina  ovalia,  posterior  and  external  to  the 
foramina  rotunda,  give  passage  to  the  third  divi- 
sion of  the  fifth  and  the  arteria  meningea  parva. 

Foramina  spinosa,  in  the  spinous  processes,  give 
passage  to  the  middle  meningeal  arteries. 

Lesser  ivings,  ov  processes  of  Ingrassias,  two  thin 
plates  of  hone,  extend  horizontally  outwards  and 
end  in  a  "pointed  process.  Internally  they  termi- 
nate in  two  rounded  eminences,  the  anterior  cli- 
noid  processes,  immediately  in  front  of  which  are 
the  optic  foramina,  which  give  passage  to  the  optic 
nerves  and  ophthalmic  arteries.  The  anterior  bor- 
ders are  serrated  to  articulate  with  the  frontal 
bone  ;  the  posterior  are  free  and  rounded,  and  af- 
ford attachment  to  the  sphenoidal  folds  of  the  dura 
mater.  The  upper  surface  is  smooth,  to  support 
the  cerebral  lobes;  the  inferior  forms  the  upper 
boundaries  of  the 

Sphenoidal  fissures,  or  foramina  lacera,  the  lower 
boundary  being  formed  by  the  greater  wings ; 
each  transmits  the  third,  fourth,  first  division  of 
the  fifth,  the  sixth  nerv^es,  the  ophthalmic  vein, 
and  some  sympathetic  fibres. 

Pterygoid  processes^  one  on  each  side,  descend. 


63 

from  the  angle  of  junction  of  the  great  alas  and  the 
body ;  each  divides  into  two  plates,  an  external, 
broad  and  irregular;  and  internal,  long  and  narrow, 
which  terminates  in  a  hook-like  process,  the  liam- 
ular  process. 

Pterygoid  fossa,  is  the  hollow  between  the  ptery- 
goid plates  posteriorly. 

Scaphoid  fossa,  at  the  base  of  the  internal  ptery- 
goid plate,  gives  origin  to  the  tensor  palati. 

Pterygo-palatine  canals,  two  grooves  at  the  inner 
aspect  of  the  internal  pterygoid  plate,  for  the  x^as- 
sage  of  the  nerve  and  vessels  of  the  same  name. 

Vidian  canals,  at  the  roots  of  the  pterygoid 
processes  for  the  passage  of  the  Vidian  nerves  and 
vessels. 

Cornua  sphenoidalia,  two  thin  plates  of  bone, 
which  close  in  the  sphenoidal  sinuses. 

The  sphenoid  articulates  with  all  the  bones  of 
the  cranium,  and  with  five  of  the  face — viz.,  the 
vomer,  two  malar,  and  two  palate;  occasionally 
with  the  two  superior  maxillary  bones. 

Development. — By  ten  centres;  two  for  posterior 
part  of  the  body,  two  for  anterior  part  of  body 
and  lesser  wings,  two  for  the  greater  wings,  two 
for  the  pterygoid  processes,  and  two  for  the  sphe- 
noidal spongy  bones. 

ETHMOID    BONE. 

Situation,  in  the  ethmoidal  notch  of  the  frontal 


64 

bone.  It  consists  of  a  body,  or  central  part,  and 
two  lateral  masses. 

Crista  gain,  vertical  process  which  divides  the 
cerebral  aspect  into  two  equal  portions,  to  which  is 
attached  the  commencement  of  the  falx  cerebri. 

Cribriform  plate ^  on  each  side  of  the  crista  galli, 
concave,  tolodg'c  tlie  olfactory  bulbs,  and  perforated 
with  holes  for  the  passage  of  the  filaments  of  the 
olfactory  nerves,  the  nasal  division  of  the  ophthal- 
mic nerve,  and  some  small  blood-vessels. 

Perpendicular  plate,  descends  from  the  under 
surface  of  the  crista  galli,  joins  the  sphenoid  bone 
posteriorly,  the  vomer  and  nasal  cartilage  inferiorly, 
and  the  os  frontis  and  nasal  bones  anteriorly ;  it  is 
thinner  in  the  middle  than  at  the  edges,  and  usually 
inclined  to  one  side.  It  is  deeply  grooved  superi- 
orly for  the  olfactory  nerves. 

Orbital  plate,  or  gs  planum,  a  smooth  square 
plate  of  bone  situated  externally  and  forming  part 
of  the  orbit ;  in  its  upper  edge  are  two  notches, 
which,  with  those  in  the  frontal  bone,  form  the 
anterior  and  posterior  ethmoidal  foramina. 

Ethmoidal  cells,  between  the  orbital  plate  and 
the  perpendicular  plate,  being  ten  or  twelve  in 
number.  They  are  divided  into  anterior  and 
posterior.  The  former,  the  more  numerous,  com- 
municate by  means  of  the  infundibulum  with  the 
frontal  sinuses ;  the  latter,  few  and  small  in  size, 
open  into  the  sphenoidal  sinuses. 


65 

Superior  spongy  hone,  descends  in  a  curved  man- 
ner outwards  from  the  upper  and  posterior  part 
of  the  bone,  forming  a  short  channel,  called  the 
superior  meatus  of  the  nose. 

Middle  spongy  hone,  larger  and  more  curved,  de- 
scends outwards,  forming  the  middle  meatus  of 
the  nose. 

Infundihidum^  a  smooth  groove  leading  from  the 
anterior  ethmoidal  cells  to  the  middle  meatus. 

Unciform  process,  an  elongated  lamella  of  bone, 
descending  from  the  lateral  mass  to  articulate 
with  the  inferior  spongy  bone. 

The  ethmoid  articulates  with  thirteen  bones — 
•viz.,  sphenoid,  frontal,  vomer,  two  nasal,  two  su- 
perior maxillary,  two  lachrymal  bones,  two  pal- 
ate, and  two  inferior  spongy  bones. 

Development. — By  three  centres — one  for  the 
horizontal  plate  and  one  for  each  lateral  mass. 


BONES   OF   THE   FACE. 
MALAR   BONE. 

Situation,  at  the  outer  and  under  part  of  the 
orbit,  forming  the  prominent  part  of  the  cheek. 

It  is  a  quadrangular  bone,  and  has  two  surfaces 
and  four  processes. 

External  surface,  convex,  and  of  irregular  quad- 
rilateral form. 

F 


Q6 

Frontal  process,  at  the  upper  and  outer  edge, 
joins  the  frontal  bone. 

Maxillary  process,  serrated,  and  rests  at  inner 
edge  on  the  superior  maxillary  bone. 

Zygomatic  process,  passes  backwards,  and  sup- 
ports the  zygomatic  process  of  the  temporal  bone 
by  a  serrated  edge. 

Upper  border,  forms  the  outer  and  inferior  mar- 
gin of  the  orbit. 

Orbital  process,  a  thin  plate  of  bone,  which 
passes  from  the  upper  edge  backwards  and  in- 
wards. 

Lower  border,  thick  and  uneven,  for  the  origin 
of  the  masseter  muscle. 

Temporal  aspect,  behind  the  zygomatic  process, 
is  smooth,  for  the  lodgment  ofthe  temporal  muscle. 

Foramina,  temporo-malcir ,  one  or  two  on  the  or- 
bital process,  which  open,  one  on  the  posterior 
surface,  and  one  on  the  cutaneous  aspect — for  ves- 
sels and  branches  of  lachrymal  nerves.  It  articu- 
lates Avilh  the  frontal,  superior  maxillary,  temporal, 
and  sphenoid  bones. 

Development. — By  one  centre. 

SUPERIOR   MAXILLARY  BOJ^E. 

Bodtj,  quadrilateral  and  hollow,  forms  anteriorly 
the  facial  surface  ;  it  presents  a  slight  depression 
above  the  sockets  of  the  incisor  teeth,  the  myrtiform 


67 

or  incisive  fossa  for  the  depressor  alas  nasi; 
external  to  this,  the  canine  fossa  for  the  levator 
anguli  oris  muscle;  and  the  opening  of  the  infra- 
orbital canAl  for  the  infra-orbital  vessels  ami  nerve. 

Orbital  surface,  triangular  and  horizontal,  forms 
part  of  the  floor  of  the  orbit. 

Infra-orbUal  canal,  passes  from  behind  forwards 
between  the  plates  of  the  orbital  surf;ice  and  ter- 
minates in  the  infra-orbital  foramen.  It  gives  off 
a  smaller  canal,  anterior  dental,  which  conducts 
a  smaller  nerve  to  the  incisor  teeth. 

Zygomatic  surface^  convex,  separated  from  the 
facial  surface  by  a  vertical  ridge;  presents  a  num- 
ber of  small  foramina,  the  posterior  dental  fora- 
mina, which  give  passage  to  the  posterior  dental 
vessels  and  nerves;  inferiorly  and  posteriorly  is 
the  tuberosity  which  corresponds  to  tbe  dens  sa- 
pientise. 

Nasal  surface,  presents  an  oblique  ridge  for  the 
inferior  turbinated  bone,  and  posteriorly  a  groove 
for  the  lodgment  of  the  lachrymal  duct;  behind 
the  groove  is  the  opening  into  the  antrum. 

Malar  process,  external  and  superior,  presents  a 
triangular  rough  surface  for  the  malar  bone. 

Nasal  process,  internal  and  superior,  is  serrated 
above  to  join  the  frontal  bone,  and  presents  a  rough 
margin  in  front  of  the  nasal  bone ;  posteriorly  it  is 
smooth  to  articulate  with  the  lachrymal  bone.  Its 
cutaneous  aspect  is  perforated  by  two  or  three  small 
f3 


foramina  for  blood-vessels  ;  its  nasal  aspect  pre- 
sents a  ridge  for  the  middle  turbinated  bone. 

Alveolar  process,  forms  the  lower  part  of  the 
body,  and  is  hollowed  out  into  sockets  for  eight 
teeth. 

Palatine  process,  horizontal,  is  thick  internally, 
and  rough  where  it  joins  its  fellow ;  its  circum- 
ference corresponds  to  the  alveolar  processes,  and 
its  posterior  edge  is  thin  and  serrated  where  it 
joins  the  palate  bone;  its  upper  surface  is  smooth 
and  concave  from  side  to  side,  forming  part  of  the 
floor  of  the  nose,  and  its  under  surface  is  rough, 
forming  part  of  the  hard  palate. 

Nasal  crest,  at  the  union  of  the  palatine  pro- 
cesses, projects  upwards  to  receive  the  vomer. 

Nasal  spine,  projects  forwards  above  and  be- 
tween the  central  incisor  teeth. 

Foramen  incisivum,  is  common  to  both  bones, 
and  exists  inferiorly  at  the  anterior  union  of  their 
palatine  plates  ;  superiorly  it  bifurcates  and  opens 
by  two  foramina,  one  to  eacb  nostril. 

Simis  maxillaris,  or  antrum  Highmori,  a  .large 
pyramidal  cavity  in  the  body  of  the  bone,  bounded 
above  by  the  orbital  plate,  below  by  the  alveoli  of 
the  molar  teeth,  anteriorly  by  the  canine  fossa,  and 
posteriorly  by  the  temporal  aspect ;  externally  it 
corresponds  to  the  malar  process,  and  internally  it 
presents  a  large  irregular  opening. 

The  superior  maxilla  articulates  with  nine  or  ten 


bones — viz.,  with  its  fellow  of  the  opposite  side, 
with  th3  frontal,  os  nasi,  lachiymil,  ethmoid, 
with  the  malar,  vomer,  inferior  spongy  bone, 
palate,  and  occasionally  -with  the  sphenoid. 

Development. — By  four  centres — one  for  the  facial 
and  nasal  portions,  one  for  the  orbital  portion,  one 
for  the  incisive  portion,  and  one  for  the  palatine 
portion. 

PALATE   BONE. 

Horizontal,  or  palate  plate,  quadrilateral,  is  con- 
cave and  smooth  above,  and  completes  the  floor  of 
the  nose,  and  rough  below,  where  it  completes  the 
hard  palate.  Its  anterior  edge  is  serrated  to  join 
the  superior  maxillary  bone  ;  its  posterior  edge  is 
concave,  and  gives  attachment  to  the  soft  palate; 
its  inner  edge  is  serrated  where  it  joins  its  fellow, 
and  sends  a  a-est  upwards  to  support  the  vomer; 
its  outer  edge  joins  the  nasal  plate. 

Nasal  spine,  projects  backwards  from  the  union 
of  the  palate  plates,  and  gives  origin  to  the  azygos 
muscle. 

Vertical  process,  broad  and  thin ;  its  inner  sur- 
face is  divided  into  two  by  a  ridge  which  supports 
the  inferior  spongy  bone ;  above  and  below  this 
ridge  the  process  is  slightly  concave,  to  assist  in 
forming  the  inferior  and  middle  meatuses ;  its 
external  surface  is  rough,  and  marked  by  the  pos- 
terior palatine  vessels   and  nerves  ;   its    anterior 


70 

thin  edge  assists  to  close  the  antrum,  and  the  pos- 
terior edge  joins  the  pterygoid  processes  of  sphenoid 
bone. 

P levy (joicl  process,  the  thickest  part  of  the  bone, 
of  a  wedge  shape,  inclines  backwards  and  out- 
wards; it  pressnts  three  grooves — a  central  one, 
smooth,  which  completes  the  pterygoid  fossa,  and 
a  rough  one  on  either  side  to  articulate  with  the 
extremities  of  the  pterygoid  plates. 

Palatine  foramina  y  at  the  junction  of  pterygoid 
and  palatine  processes,  give  passage  to  the  poste- 
rior palatine  nerve  and  vessels. 

The  vertical  plate  divides  at  its  upper  part  into 
two  processes — an  anterior  or  orbital,  and  a  pos- 
terior or  sphenoidal  process.  The  notch  at  the 
point  of  bifurcation  is  the  spheno-palatine,  com- 
pleted into  a  foramen  by  the  sphenoid  bone. 

Orbital  process,  is  large  and  hollow,  and  of  tri- 
angular form  ;  it  presents  five  surfaces,  three  ar- 
ticulated, two  free.  The  anterior  articulates  with 
the  superior  maxilla,  the  posterior  with  the  sphe- 
noid, the  internal  with  the  ethmoid.  The  superior 
forms  part  of  the  floor  of  the  orbit ;  the  external 
looks  into  the  zygomatic  fossa. 

Sphenoidal  process,  articulates  with  the  body  of 
the  sphenoid  bone,  and  is  also  hollow,  forming  the 
pterygo-palatine  canal. 

It  articulates  with  seven  bones — viz.,  the  corre- 
sponding palate  bone,  the  superior  maxilla,  eth- 


71 

moid,  sphenoid,  vomer,  inferior  spongy  bone,  and 
the  sphenoidal  spongy  bone. 
Development. — By  one  centre. 

INFEHTOR    SPOXGY    BO^E. 

Hough  and  convex  towards  the  septum  of  the 
nose,  and  concave  externally  ;  presents  a  free  mar- 
gin inferiorly,  and  is  attached  above  to  the  lachry- 
mal bone  and  ethmoid,  and  to  the  ridge  on  the 
superior  maxillary  and  palate  bones.  It  completes 
the  nasal  duct  inferiorly,  and  helps  to  close  in  the 
antrum  by  its  maxillary  process. 

Development. — By  one  centre. 

LACHRYMAL  BONE. 

Situation,  inner  and  front  part  of  orbit. 

Edges,  serrated  to  join  the  os  frontis  above,  the 
ethmoid  bone  behind,  and  the  inferior  spongy  bone 
below ;  smooth  to  join  the  nasal  process  of  the 
superior  maxillary  in  front. 

External  surface,  divided  by  a  perpendicular 
ridge,  presents  a  groove  anteriorly  for  the  lachry- 
mal sac,  and  a  smooth  surface  behind  to  assist  in 
forming  the  orbit. 

Inteimal  surface,  closes  in  the  anterior  ethmoidal 
cells. 

Development. — By  one  centre. 


73 

NASAL   BONE. 

Situation,  above  the  nasal  process  of  frontal 
bone,  and  between  tlie  nasal  processes  of  superior 
maxillary  bonps. 

External  surface,  convex,  presents  small  fora- 
mina for  blood-vessels. 

Internal  surface,  concave,  and  grooved  for  the 
nasal  nerves. 

Superior  edge,  thick  and  serrated,  to  join  the 
frontal  bone. 

Inferior  edge,  thin  and  expanded,  joins  the  late- 
ral nasal  cartilage. 

External  edge,  is  the  longest,  and  is  serrated 
to  join  the  superior  maxillary  bone. 

Internal  edge,  is  flat,  and  joins  its  fellow. 

The  nasal  bone  articulates  Avith  the  frontal 
superior  maxilla,  ethmoid  bone,  and  fellow. 

Development. — By  one  centre. 


Situation,  in  the  middle  line  of  nose,  forming 
part  of  its  septum, 

Superior  edge,  grooved  to  receive  the  azygos 
process  of  the  sphenoid  bone. 

Anterior  edge,  slightly  grooved  to  receive  the 
ethmoidal  plate  and  nasal  cartilage. 

Posterior  edge,  free,  looks  towards  the  pharynx. 


73 

Inferior  edge,  the  longest,  is  received  into  the 
nasal  crest  of  the  superior  maxillary  and  palate 
bones. 

Naso'palatine  groove,  runs  along  the  outer  sur- 
face in  its  long  axis. 

Development. — By  two  centres. 

INFERIOR   MAXILLARY   BONE. 

Bodtjy  the  anterior  portion  projects  inferiorly 
into  mental  process  or  chin,  superiorly  is  surmount- 
ed by  alveoli  of  four  incisor  teeth,  anteriorly  has 
on  each  side  a  depression  for  muscles,  and  pos- 
teriorly two  depressions  for  the  digastric  muscles, 
above  which  are  two  pairs  of  tubercles — the  in- 
ferior for  the  gcnio-hyoidci,  and  the  superior  for 
the  genio-hyo-glossi  muscles. 

Symphysis,  a  vertical  ridge  in  the  centre  of 
body. 

Horizontal  rami. — On  the  outer  surface  of  each 
is  an  oblique  ridge  for  muscles;  on  the  inner  is  the 
mylo-hyoidean  ridge,  above  which  is  a  depressiou 
for  the  sublingual  gland,  and  another  below  for  the 
submaxillary  gland.  The  lower  edge  is  rounded 
and  grooved  for  the  facial  artery,  and  upon  the 
upper  edge  are  alveolar  processes. 

Angle,  obtuse  and  rough  for  muscles. 

Ascending  rami,  are  thick  and  round  posteriorly, 
externally  smooth,  internally  grooved. 


74 

Coronold  process,  passes  upwards  from  anterior 
J)art  of  ascending  ramus. 

Condyle,  transversely  oblong  to  articulate  with 
temporal  bone. 

Neck,  constricted  part  below  condyle. 

Sigmoid  notch,  between  condyle  and  coronoid 
process. 

Inferior  dental  foramen,  situated  at  internal  sur- 
face of  ascending  ramus,  and  surmounted  by  a 
spine. 

Mental  foramen,  situated  at  anterior  surface  of 
bone  external  to  body. 

Dental  canal,  traverses  bone  between  the  two 
foramina,  and  communicates  with  each  a'vcolus. 

It  articulates  with  the  glenoid  fossae  of  the  two 
temporal  bones. 

Development. — By  two  centres,  which  coalesce  at 
the  symphysis. 

OS   HYOIDES. 

Situation,  in  the  anterior  part  of  the  neck  be- 
tween the  chin  and  larynx. 

Body,  square,  is  rough  anteriorly  for  muscles, 
and  smooth  behind  where  it  corresponds  to  the 
epiglottis. 

Greater  cornua,  pass  obliquely  backwards  from 
the  sides  of  the  body,  and  end  in  tubercles. 

Lesser  cornua,  are  very  small,  and  pass  obliquely 
backwards  and  upwards  from  the  point  of  junction 


75 

of  the  great  cornua  and  body,  and  connect  the 
bone  -with  the  styloid  process  of  temporal  bone  by 
means  of  the  stylo-hyoid  ligaments. 

Development. — By  five  centres,  one  for  the  body 
and  one  for  each  cornu. 

The  bones  of  the  ear  are  described  in  connexion 
with  the  organ  of  hearing. 

SUTURES  OF  THE  CRANIUM  AND  FACE. 

Coronal  suture,  commences  a  little  behind  the 
external  angular  process  of  the  frontal  bone,  at  the 
upper  termination  of  the  great  wing  of  the  sphen- 
oid bone,  and,  inclining  backwards,  extends  across 
the  cranium  to  the  opposite  corresponding  point, 
connecting  in  its  course  the  frontal  with  the  pari- 
etal bones. 

Lamhdoid  suture,  commences  at  the  union  of  the 
petrous  portion  of  the  temporal  bone  with  the 
parietal  and  occipital  bones,  and  extending  across 
the  posterior  part  of  the  cranium  to  the  opposite 
corresponding  point,  connects  the  occipital  with 
tlie  parietal  bones. 

Sagittal  suture,  extends  from  the  angle  of  the 
occipital  bones  forwards,  connecting  in  its  course 
the  parietal  bones,  and  corresponding  to  the  me- 
dian line  ;  it  generally  terminates  in  the  coronal 
suture,  but  is  occasionally  prolonged  to  the 
nasal  bones,  dividing  the  frontal  bone. 


76 

Squamous  suture,  corresponds  to  the  semicircular 
edge  of  the  squamous  portion  of  the  temporal 
bone,  and  connects  it  with  the  great  wing  of  the 
sphenoid  bone  and  with  the  parietal  bone. 

Masto-occipital  suture,  extends  from  the  termi- 
nation of  the  lambdoid  suture  to  the  foramen 
laccrum  posterius,  and  unites  the  mastoid  process 
of  the  temporal  bone  to  the  occipital. 

Masto-parietal  suture,  extends  nearly  horizon- 
tally backwards  from  the  posterior  termination  of 
the  squamous  suture  to  the  lambdoid  suture,  con- 
necting the  upper  extremity  of  the  mastoid  portiou 
of  the  temporal  bone  with  the  parietal  bone. 

Sphenoid  suture,  extends  around  the  irregular 
margins  of  the  sphenoid  bone,  connecting  it  with 
all  the  bones  of  the  head,  and  with  the  malar, 
superior  maxillary,  and  palate  bones. 

Ethmoid  suture,  surrounds  the  ethmoid  bone, 
connecting  it  with  the  frontal,  nasal,  superior 
maxillary,  lachrymal,  and  palatine  bones,  and 
with  the  vomer. 

Transverse  suture,  connects  the  bones  of  the 
face  with  those  of  the  head. 

Zygomatic  suture,  corresponds  to  the  junction  of 
the  temporal  with  the  malar  bone. 

ORBITS. 

The  orbits  are  two  pyramidal  cavities^  the  bases 
of  which  look  outwards  and  forwards,  and  their 


77 

apices  in  the  contrary  direction  ;  so  that  two  lines 
passing  through  their  axes  if  prolonged  posteriorly 
would  meet  at  the  sella  turcica.  Each  orbit  is 
formed  of  seven  bones,  three  of  which — viz.,  the 
frontal,  sphenoid,  and  ethmoid,  arc  common  to  both 
orbits;  theotherfour — viz.,  the  lachrymal,  superior 
maxillary,  malar,  and  palate  bones  belonging  to 
the  orbit  of  their  corresponding  side.  The  roof  is 
formed  by  the  lesser  wing  of  the  sphenoid  bone  and 
the  orbital  plate  of  the  frontal.  At  the  outer  angle 
is  a  depression  for  the  lachrymal  gland  ;  at  the 
inner  a  depression  for  the  pulley  of  the  superior 
oblique  muscle.  The  floor  is  formed  by  the  superior 
maxilla,  the  malar,  and  palate  bones,  and  contains 
the  infra-orbital  canal.  The  outer  wall  is  formed 
by  the  malar  and  sphenoid  bones;  it  is  pierced  by 
some  small  foramina  for  nerves;  the  inner  is 
formed  by  the  os  planum  of  the  ethmoid,  the 
lachrymal  bone,  superior  maxilla,  and  a  piece  of 
the  sphenoid.  It  is  perforated  by  the  anterior  and 
posterior  ethmoidal  foramina.  The  foramina  in 
the  base  of  the  orbit  are,  the  supra-orbital,  the 
infra-orbital,  and  the  upper  orifice  of  the  nasal 
duct,  and  the  temporo-malar;  within  the  orbit  are 
the  optic  foramen,  the  sphenoidal  fissure,  and  the 
spheno-maxillary  fissure.  Through  the  optic  fora- 
men passes  the  optic  nerve  and  ophthalmic  artery. 
Through  the  fissura  sphenoidalis  the  third,  fourth, 
ophthalmic  division  of  the  fifth  nerve,  the  sixth 


78 

nerve,  and  the  ophthalmic  vein,  and  some  filaments 
of  the  sympathetic. 

TEMPORAL   FOSSA, 

Placed  on  the  side  of  the  cranium,  is  bounded  by 
the  frontal,  sphenoid,  malar,  parietal,  and  temporal 
bones,  and  lodges  the  temporal  muscle.  It  is  tra- 
versed by  five  sutures,  the  transverse  facial,  the 
spheno-parietal,  squamo- parietal,  squamo-sphe- 
noid,  and  coronal. 

ZYGOMATIC    FOSSA, 

Extends  from  the  temporal  fossa  downwards,  and 
is  bounded  by  the  zygomatic  arch,  the  superior 
maxillary  bone,  and  the  portion  of  the  great  wing 
of  the  sphenoid  bone  below  its  crest.  Between  the 
great  wing  of  the  sphenoid  and  the  border  of  the 
superior  maxillary  bone  is  the  spheno-maxillary 
fissure,  which  opens  into  the  orbit. 

PTERYGO-MAXILLARY    FISSURE, 

Lies  deep  in  the  zygomatic  fossa,  is  bounded  by 
the  pterygoid  processes,  the  tuberosity  of  the  su- 
perior maxilla,  and  the  nasal  process  of  the  palate 
bone ;  and  communicates  with  the  spheno-maxil- 
lary fis-ure.  The  angle  of  union  of  the  spheno- 
maxillary aMd  ptcrygo-maxillary  fissures  is  called 


79 

the  splieno-maxiUanj  fossa,  into  which  five  fora- 
mina open  :  foramen  rotundum,  for  second  branch 
of  fifth  cerebral  nerve;  Vidian  canal,  for  the 
Vidian  nerve  ;  pterygo-palatine,  for  a  small  artery; 
posterior  palatine,  for  nerves  and  arteries  ;  spheno- 
palatine, which  lodges  the  spheno-palatine  gan- 
glion ;  also  two  fissures,  the  pterygo-maxillary 
and  spheno-maxillary. 

NASAL   FOSSiE, 

Are  two  cavities  which  extend  from  the  palate 
processes  of  the  superior  maxillae  and  palate  bones 
to  the  base  of  the  cranium.  They  open  in  front  by 
the  two  anterior  nares,  and  posteriorly  ])y  the  two 
posterior  narcs,  and  are  separated  from  each  other 
by  the  septum  nasi. 

The  roof  is  formed  by  the  nasal  bones,  the  nasal 
spine  of  the  frontal,  the  cribriform  plate  of  the 
ethmoid,  the  body  of  the  sphenoid,  and  the  sphe- 
noidal spongy  bones. 

The.  floor  is  formed  by  the  palate  processes  of 
l^the  super  or  maxi  lary  and  palate  bones. 

The  outer  icall  is  formed  by  the  nasal  bone,  the 
nasal  process  of  the  superior  maxilla,  the  lachry- 
mal, the  ethmoid,  the  inner  surface  of  the  supe- 
rior maxilla  and  inferior  turbinated  bones,  and  by 
the  vertical  plate  of  the  palate  bone. 

The  septum  is  formed  by  the  nasal  spine  of  the 
frontal,  the  ridge  of  the  nasal  bones,  the  rostrum 


80 

of  the  sphenoid,  vomer,  perpendicular  plate  of  the 
ethmoid,  and  the  ridge  formed  by  the  two  superior 
maxillas  and  palates  bones. 


ARTICULATIONS 

These  may  be  divided  into  three :  synarthrosis y 
ampldarthrosis,  and  diarthrosis. 

1.  Synarthrosis,  or  immovable  articulations,  com- 
prise those  which  are  immovably  connected,  and 
allow  of  no  movement  between  each  other.  This 
class  is  subdivided  into  sutura,  schindylesis,  and 
gomphosis.  Of  the  sutura  there  are  two  varieties — 
the  true,  which  articulate  by  indented  borders,  and 
the  false,  whose  surfaces  are  simply  apposed.  The 
true  sutures  include  the  dentata,  serrata,  and  lim- 
bosa ;  the  false  comprise  the  squamosa  and  har- 
monia. 

Schindylesis,  where  a  thin  plate  of  bone  is  re- 
ceived into  a  cleft  formed  by  two  diverging  plates, 
as  the  rostrum  with  the  vomer. 

Gomphosis,  as  the  teeth  are  received  into  the 
alveoli. 

2.  AmphiarthrosiSy  or  partly  moveable  articula- 
tions, include  those  surfaces  connected  by  fibro- 
cartilage,  as  between  the  bodies  of  the  vertebrae 
and  those  invested  with  fibro-cartilage,  lined  by  a 
partial  synovial  membrane,  as  in  the  pubic  sym- 
physis. 


81 

3.  DlaHhrosis,  or  moveable  joints.  Includes 
arthrodia,  or  gliding  joints,  as  in  cai-pus  and  tar- 
sus ;  ginghjmus,  or  hinge-joint,  as  in  the  elbow- 
joint  ;  enartkrosis,  or  ball-and-socket  joint,  as  the 
shoulder  and  hip ;  and  dlarthrosis  rotatorius,  or  lat- 
eral ginglymus,  which  allows  movements  around 
a  pivot  process,  as  in  the  atlo-axoid  joint. 

TEMPORO-MAXILLARY   ARTICUALTION. 

Bony  formation,  glenoid  cavity  of  temporal  bone, 
and  condyle  of  inferior  maxilla. 

External  lateral  ligament, — origin,  zygomatic  pro- 
cess and  tubercle  of  temporal  bone.  Insertion^ 
outer  side  of  the  neck  of  condyle  of  lower  jaw. 

Internal  lateral  ligament, — origin,  spinous  process 
of  sphenoid  bone.  Insertion,  margin  of  inferior 
dental  foramen. 

Stglo^maxillary  ligament, — origin,  styloid,  pror 
cess  of  temporal  bone.  Insertion,  angle  of  inferior 
maxilla. 

Capsular  ligament, — origin,  zygomatic  eminence 
and  glenoid  fissure.     Insertion,  neck  of  lower  jaw. 

Synovial  membranes ;  two,  one  is  reflected  from 
the  cartilaginous  surface  of  zygomatic  eminence 
and  glenoid  cavity  over  the  superior  surface  of  the 
fibro-cartilage ;  the-  other  covers  the  under  surface 
of  the  fibro-cartilage,  and  is  reflected  over  the 
condyle. 

G 


83 

Inter-articular,  or  Jihro-canilage,  of  oval  figure, 
thick  in  its  circumference,  thin  in  the  centre, 
where  it  is  sometimes  perforated.  Divides  the 
joint  into  two. 

Nerves,  from  the  auriculo-temporal  and  masse- 
teric branch  of  the  inferior  maxillary. 

OCCIPITO-ATLOID    ARTICULATION 

Bony  formation,  condyles  of  occipital  bone  and 
superior  articular  process  of  atlas. 

Two  capsular  ligaments,  imperfect. 

Synovial  membranes,  cover  the  opposed  cartila- 
ginous surfaces. 

Tivo  anterior  occipito-atloid  ligaments, — origin,  an- 
terior edj^-e  of  foramen  magnum.  Insertion,  upper 
edge  of  atlas,  anterior  to  its  articular  processes. 

Posterior  occipito-atloid  ligament, — origin,  poste- 
rior edge  of  foramen  magnum.  Insertion,  upper 
edge  of  atlas  behind  its  articular  processes. 

Two  lateral  ligaments, — origin,  jugular  process  of 
occiput.     Insertion,  transverse  process  of  atlas. 

OCCIPITO-AXOID    ARTICULATION. 

Chech,  or  oblique  ligaments,  (Syn.)  Ligamenta  ala- 
ria ;  odontoid  ligaments,— origin,  from  each  side  of 
head  of  odontoid  process.  Insertion,  inner  side  of 
each  occipital  condyle.  A  third  ligament  (liga- 
mentum  suspensorium)  passes  from  the  tip  of  the 


83 

odontoid  process  to  the  margin  of  the  foramen, 
magnum. 

Apparatus  ligamentosus  colli,  or  occlpito-axoid 
ligament, — origin,  lower  part  of  basilar  process, 
posterior  to  odontoid  process.  Insertion,  bodies  of 
second  and  third  vertebra},  where  it  is  continuous 
with  the  posterior  common  ligament. 

ATLO-AXOID    ARTICULATION. 

Bony  formation,  the  anterior  portion  of  the  canal 
of  the  atlas,  and  the  odontoid  process  of  axis ;  no 
inter-vertcbral  substance. 

Anterior  and  posterior  ligaments,  as  in  all  the 
other  vertebra}. 

Transverse  ligament,  attached  on  each  side  to 
inner  edge  of  articular  process  of  the  atlas,  and  to 
basilar  process  above,  and  body  of  axis  below. 

Two  capsidar,  thin,  between  the  articulating  sur- 
faces of  the  two  bones. 

Synovial  membranes,  one  between  posterior  sur- 
face of  odontoid  process,  and  anterior  surface  of 
transverse  ligament ;  the  other  covers  the  opposed 
cartilaginous  surfaces  of  the  atlas  and  odontoid 
process. 

COMMON    VERTEBRAL    ARTICULATION. 

Bony  formation,  opposed  surfaces  of  the  bodies 
connected  by  the  inter-vertebral  fibro-cartilages, 
and  articular  processes  of  the  vertebrae. 
g3 


84 

Anterior  common  ligament^  a  strong  hznH  of 
fibres  extending  along  the  front  of  the  spinal 
column  from  axis  to  sacrum.  It  adheres  strongly 
to  the  bodies  and  inter- vertebral  substances. 

Posterior  common  ligament,  extends  along  the 
posterior  surface  of  bodies  of  vertebrae  within  the 
spinal  canal.  It  is  separated  from  the  bodies  of 
the  vertebra)  by  some  large  veins. 

Inter-vertehraljihro-cartilages,  are  placed  between 
the  bodies  of  all  the  vertebrae,  except  the  atlas 
and  the  axis,  and  united  to  the  flat  surfaces  above 
and  below.  They  are  thicker  in  front  than  behind 
in  the  cervical  and  lumbar  regions,  the  reverse 
in  the  dorsal,  where  they  are  attached  to  the 
heads  of  the  ribs. 

Ligamenta  suhflava,  composed  of  yellow  elastic 
tissue,  are  situated  between  the  lamina)  of  adjacent 
vertebrae  from  the  axis  to  the  sacrum.  They  in- 
crease in  thickness  in  the  lower  part  of  the  spine, 
and  complete  the  posterior  part  of  the  spinal  canal. 

Capsular  ligaments,  connect  the  opposed  articu- 
lar surfaces,  and  are  lined  by  synovial  membrane. 

Supraspinous  and  inter-spinous  ligaments  ;  the 
former  connect  the  summits  of  the  spinous  process, 
the  latter  pass  between  the  borders  of  the  spinous 
processes. 

Inter -transverse  ligaments,  connect  the  trans- 
verse processes  ;  sometimes  absent  in  the  cervical 
region. 


85 


COSTO-SPINAL  ARTICULATIONS. 

Bony  formation^  heads,  and  tubercles  of  ribs 
with  bodies  and  transverse  processes  of  vertebraB'. 

Anterior  costo-vertebral,  or  stellate  ligament, — ori- 
gin, anterior  part  of  head  of  rib.  Insertion,  side 
of  the  bodies  of  the  vertebrje  above  and  below, 
and  to  the  inter-vertebral  substance  by  radiating 
fibres. 

Inter-articular  ligament, — origin,  from  projecting 
ridge  on  the  articular  surface  of  each  rib.  Insertion^ 
into  the  inter- vertebral  substance  into  which  the 
head  is  received.  It  divides  the  joint  into  two  se- 
parate divisions,  which  are  lined  with  distinct  sy- 
novial membranes.  Absent  in  the  first,  eleventh, 
and  twelfth  ribs. 

Costo-transverse  ligaments,  three  in  number. 

Anterior  costo-transverse  ligament, — origin,  neck 
of  each  rib.  Insertion^  transverse  process  of  the 
vertebra  above.     Absent  in  the  first  rib. 

Posterior  costo-transverse  ligament,  connects  the 
tubercle  of  each  rib  with  the  apex  of  the  corre- 
sponding transverse  process.  Absent  in  eleventh 
and  tweli'th  ribs. 

Middle,  or  inter -osseous,  costo-transverse  ligament^ 
connects  the  neck  of  the  rib  to  the  contiguous 
transverse  process ;  to  see  it  the  bones  must  be 
forcibly  separated.  Rudimentary  in  eleventh  and 
twelfth  ribs. 


86 

Capsular,  connects  the  tubercle  of  the  rib  with 
transverse  process  and  encloses  a  small  synovial 
membrane. 

Synovial  membranes,  are  between  the  tubercles 
and  the  transverse  processes. 

COSTO-STERNAL   ARTICULATION. 

The  ribs  are  connected  with  the  sternum  by  an- 
terior and  posterior  costo-sternal  ligaments,  which 
pass  from  the  cartilages  of  the  ribs  to  the  sternum, 
the  anterior  being  the  stronger.  Synovial  mem- 
branes exist  between  the  cartilages  and  the  ster- 
num, except  in  the  first,  where  the  cartilage  is 
continuous  with  the  bone. 

LUMBO-SACRAL  ARTICULATION. 

Bony  formation,  last  lumbar  vertebra  and  sa- 
crum. Tliese  are  united  together  in  the  same 
manner  as  the  other  vertebrae. 

The  spine  is  connected  with  the  pelvis  by  the 
ilio-lumbar  and  lumbo-sacral  ligaments. 

Mio-Iumbar  ligament, — origin,  transverse  processes 
of  fifth  lumbar  vertebrae.  Insertion,  posterior,  su- 
perior spinous  process  and  crest  of  the  ilium. 

Lumbo-sacral  ligament,- — origin,  lower  part  of 
transverse  process  of  fifth  lumbar  vertebra.  Inser 
tion,  lateral  aspect  of  base  of  sacrum. 


87 


ILIO-SACRAL   ARTICULATION. 

The  ilium  and  sacrum  are  connected  together 
by  anterior  and  posterior  sacro-iUac  ligaments ;  the 
posterior  is  much  the  stronger,  two  of  the  bands 
being  horizontal  and  the  third  oblique. 

SACRO-SCIATIC    LIGAMENTS. 

Great  sacra-sciatic  ligament, — origin,  posterior 
inferior  spine  of  ilium,  and  side  of  sacrum  and 
coccyx.  Insertion,  lower  border  of  tuber  ischii. 
Along  the  ramus  of  the  ischium  it  sends  a  falci- 
form prolongation  which  covers  the  obturator  in- 
ternus  muscle. 

Lesser  sacro-sciatic  ligament, — origin,  side  of  sa- 
crum and  coccyx.     Insertion,  spine  of  ischium. 

These  ligaments  convert  the  great  lateral  pelvic 
notch  into  two  foramina,  called  the  greater  and 
lesser  sacro-sciatic forajnina.  The  former,  superior, 
transmits  the  pyramidalis,  greater  and  lesser  sacro- 
sciatic  nerves,  tlie  gluteal  vessels  and  nerve,  the 
pudic  vessels  and  nerve  and  the  sciatic  artery,  and 
the  nerve  to  the  obturator  internus ;  the  latter,  in- 
ferior, and  bounded  by  the  two  ligaments,  transmits 
the  tendon  of  the  obturator  internus  muscle,  the 
pudic  vessels  and  nerve,  and  the  nerve  to  the 
obturator  internus  muscle. 


88 


SACRO-COCCYGEAL   ARTICULATION. 

The  sacrum  and  coccyx  are  united  together  by 
anterior  and  posterior  sacro-coccygeal  ligaments, 
and  by  a  similar  substance  to  the  inter- vertebral. 


PUBIC   ARTICULATION. 

Anterior  pubic  ligament,  consists  of  decussating 
fibres  in  front  of  pubes. 

Posterior  pubic  ligament,  unites  the  pubic  bones 
posteriorly. 

Superior  pubic  ligament,  passes  along  the  upper 
border  of  the  bones. 

Sub  -  pubic  ligament,  or  ligamentum  arcuatum, 
passes  from  the  ramus  of  one  bone  to  the  other, 
and  rounds  off  the  angle  formed  by  their  union. 

Fibro -cartilage,  which  attaches  closely  the  pubic 
bones.  It  is  composed  of  two  plates,  firmly  at- 
tached on  their  outer  aspects  to  the  pubic  bones, 
and  between  them  exists  a  synovial  cavity  at  the 
upper  and  back  part. 

Obturator  membrane,  attached  to  the  margin  of 
the  obturator  foramen,  except  superiorly,  where 
the  obturator  vessels  and  nerve  pass  through. 

STERNO-CLAVICULAR   ARTICULATION. 

Anterior  ligament, — origin,   anterior  surface  of 


89 

sternal  end  of  clavicle.     Insertion^  anterior  surface 
of  sternum. 

Posterior  ligament, — origin,  posterior  surface  of 
sternal  end  of  clavicle.  Insertion,  back  part  of 
sternum. 


Costo-clavicular  UgamenL — origin,  lower  surface 
of  sternal  end  of  clavicle.  Insertion,  cartilaf^^c  of 
first  rib. 

Inter-clavicular  ligament,  or  rhombrnd,  extends 
from  the  sternal  extremity  of  one  clavicle  to  that  of 
the  other,  dipping  down  in  its  course  to  becom- 
attachcd  to  the  upper  border  of  the  sternum. 

Inter -articular  cartilage,  thin  below  and  attached 
to  sternum  ;  thick  above  and  attached  to  clavicle ; 
having  a  synovial  membrane  connected  to  each 
surface  and  its  corresponding  bone. 

SCAPULO-CLAVICULAR  ARTICULATION . 

Superior  acromio-clavicular  ligament, — origin,  up- 
per surface  of  acromion.  Insertion,  upper  part 
of  clavicle. 

Inferior  acromio-clavicular  ligament,  attached  to 
under  surface  of  each  bone. 

Synovial  membrane  covers  the  articulating  sur- 
faces in  the  usual  manner. 

There  is  occasionally  an  imperfect  inter-articu- 
lar fibro -cartilage. 

CoracO'Clavicular  ligaments  are  divided  into  : 


90 

Conoid  ligament,  triangular;  base  connected  to 
the  tubercle  on  inferior  surface  of  clavicle,  apex  at 
the  broad  part  of  coracoid  process. 

Trapezoid  ligament,  attached  above  to  an  oblique 
line  on  the  clavicle  ;  below  to  upper  part  of  the 
coracoid  process. 

There  is  no  tru3  division  of  these  ligaments ; 
the^  consist  of  one  fibrous  layer  twisted  upon  itself. 

LIGAMENTS    OF    THE    SCAPULA. 

Coraco-acromial  ligament, — origin,  broad  from 
coracoid  process.  Insertion,  narrow  into  point  of 
acromion. 

Transverse  or  coracoid  ligament, — origin,  supe- 
rior costa  of  scapula  behind  the  notch.  Insertion, 
base  of  coracoid  process.  This  ligament  converts 
the  notch  into  a  foramen,  through  which  passes 
the  supra- scapular  nerve,  the  supra-scapular  ar- 
tery passing  over  it. 

HUMERO-SCAPULAR   ARTICULATION. 

Bony  formation,  head  of  humerus  and  glenoid 
cavity  of  scapula. 

Capsular  ligament, — origin,  circumference  of  neck 
of  scapula.  Insertion,  around  the  anatomical  neck 
of  humerus.  It  is  strengthened  by  the  coraco- 
humeral  ligament,  and  by  prolongations  from  the 


di 

tendons  of  the  supra  and  infra-spinatus  and  teres 
minor  and  subscapularis  muscles. 

Coraco-humerul  ligament, — origin,  coracoid  pro- 
cess.    Insertion,  anterior  part  of  great  tuberosity. 

Synovial  membrane,  is  reflected  over  the  surface 
of  the  glenoid  cavity  around  the  glenoid  ligament ; 
lines  the  capsular  ligament,  head  of  humerus,  and 
bicipital  groove. 

Glenoid  ligament,  closely  connected  with  the 
tendon  of  the  biceps  muscle,  encircles  the  glenoid 
cavity,  and  by  elevating  the  border,  adds  to  the 
depth  of  the  articular  surface. 

Nerves,  from  the  circumflex  and  supra-scapular. 

ELBOW-JOINT. 

Bony  formation,  articular  processes  of  humerus, 
great  sigmoid  cavity  of  ulna,  head  of  radius. 

External  lateral  ligament, — origin,  external  con- 
dyle of  humerus.  Insertion,  annular  ligament  of 
radius,  and  outer  margin  of  ulna. 

Internal  lateral  ligament, — origin,  internal  con- 
dyle. Insertion,  inner  edge  of  olecranon  and  coro- 
noid  process. 

Anterior  ligament,  consists  of  thin  fibres, — origin, 
principally  from  above  internal  condyle  and  depres- 
sion on  front  part  of  humerus.  Insertion,  annular 
ligament  of  radius  and  coronoid  process  of  ulna. 

Posterior  ligament,  is  composed  of  fibres  which 


92 

extend  from  one  condyle  to  the  other  and  are  at- 
tached to  the  margin  of  the  olecranon. 

Sijnovial  membrane,  is  reflected  from  behind  the 
anterior  ligament  to  neck  of  radius  and  annular 
ligament ;  it  then  lines  the  sigmoid  cavities  of  the 
ulna,  and  is  reflected  to  the  lateral  ligaments  and 
tendon  of  the  triceps  muscle,  which  conducts  it  to 
the  posterior  depression  of  the  humerus;  it  is  then 
expanded  over  its  articular  surfaces. 

Nerves,  from  the  ulnar  and  musculo-cutaneous. 


SUPERIOR  RADIO- ULNAR  ARTICULATION. 

Boni/ formation,  lesser  sigmoid  cavity  of  ulna, 
^nd  inner  side  of  head  of  radius, 
ipl  Annular  ligament, — origin,  anterior  border  of 
lesser  sigmoid  cavity  of  ulna.  Insertion,  posterior 
border  of  the  same  cavity.  It  encircles  the  neck 
of  radius. 

Oblique  ligament, — origin,  coronoid  process  of 
ulna.     Insertion,  radius  below  its  tubercle. 

Inter-osseous  membrane,  connects  the  opposed 
edges  of  radius  and  ulna,  its  fibres  descending 
obliquely  inwards  from  the  former  bone  to  the  latter. 

INFERIOR   RADIO-ULNAR   ARTICULATION. 

Bong  formation,  round  head  of  ulna  and  sigmoid 
cavity  of  radius  ;  the  bones  are  united  by  some  thin 


93 

fibrous  bands,  which  are  called  the  anterior  and 
posterior  radio-uhiar  ligaments. 

Fihro-cartllage, — origin,  styloid  process  of  ulna. 
Insertion,  inner  edge  of  radius  below  the  ulna. 

The  synovial  membrane,  called  sometimes  mem- 
brana  sacciformis,  extends  horizontally  between 
the  extremity  of  the  ulna  and  the  fibro-cartilagc, 
and  vertically  between  the  opposed  articulating 
surfaces  of  the  radius  and  ulna. 

RADIO  CARPAL   ARTICULATION. 

Bony  formation,  lower  end  of  radius  ;  scaphoid, 
lunar,  and  cuneiform  bones. 

The  extremity  of  the  ulna  is  excluded  from  the 
joint  by  the  fibro-cartilage. 

External  lateral  ligament,  —  origin,  styloid  pro- 
cess of  radius.  Insertion,  scaphoid  bone,  and  by 
some  fibres  into  annular  ligament  and  trapezium. 

Internal  lateral  ligament, — origin,  styloid  pro- 
cess of  ulna.  Insertion,  cuneiform,  pisiform  bones, 
and  annular  ligament. 

Posterior  ligament, — origin,  posterior  part  of  ra- 
dius and  fibro-cartilage.  Insertion,  back  part  of 
superior  row  of  carpal  bones. 

Anterior  ligament, — origin,  anterior  part  of  radius 
and  fibro-cartilage.  Insertion,  fore  part  of  first 
row  of  carpal  bones. 

The  synovial  membrane  lines  the  head  of  the 


94 

radius,   the  fibro-cartilage,  and  is   then  reflected 
over  the  three  carpal  bones. 

iVerres,  from  the  ulna  and  posterior  inter-osseous. 

CARPAL   ARTICULATIONS. 

The  bones  of  the  carpus  are  articulated  by 
ligamentous  bands,  both  anteriorly  and  poste- 
riorly. 

The  scaphoid,  lunar,  and  cuneiform  bones  arc 
connected  by  dorsal  and  palmar  ligaments,  extend- 
ing from  bone  to  bone  :  between  the  opposed  bor- 
ders are  inter  osseous  ligaments. 

The  pisiform  bone  possesses  a  distinct  fibrous 
capsule  and  synovial  membrane. 

The  trapezium,  trapezoid,  os  magnum,  and  un- 
ciform are  also  connected  by  dorsal  and  palmar 
ligaments. 

Inter-osseous  ligaments  are  found  on  each  side 
of  the  OS  magnum. 

Lateral  ligaments  extend  on  the  radial  side  from 
the  scaphoid  to  the  trapezium;  on  the  ulnar  side 
from  the  cuneiform  to  the  unciform. 

The  carpal  synovial  membrane  extends  between 
the  first  and  second  row  of  carpal  bones,  and  is 
prolonged  to  the  carpal  extremities  of  the  four  in- 
ner metacarpal  bones.  The  trapezium  articulates 
with  the  metacarpal  bone  of  the  thumb  by  a  dis- 
tinct capsule  and  synovial  membrane. 


95 

Annular  ligament, — origin,  trapezium  and  sca- 
phoid bones.  Insertion,  cuneiform  and  unciform 
bones. 

CARPO-METACARPAL  ARTICULATION. 

The  carpus  and  metacarpus  are  secured  by 
fibrous  bands,  which  pass  in  different  directions, 
and  cover  the  synovial  membranes. 

METACARPOPHALANGEAL   ARTICULATIONS. 

Tlic  heads  of  the  metacarpus  and  first  phalanges 
are  secured  by  lateral  ligaments,  and  are  lined  by 
synovial  membranes.-  a  transverse  ligament  con- 
nects the  digital  extremities  of  the  metacarpal 
bones  one  with  another  :  an  anterior  connects  the 
palmar  surfaces  of  the  two  bones. 

INTER-PHALANGEAL  ARTICULATIONS. 

The  phalanges  are  connected  to  each  other  by 
means  of  anterior  and  lateral  ligaments,  and  be- 
tween each  of  these  joints  is  a  synovial  membrane. 

HIP-JOINT. 

Bony  formation,  acetabulum  and  head  and  part 
of  neck  and  femur. 

Capsular  ligament, — origin,  circumference  of  ace- 


96 

tabulum  and  transverse  ligament.  Insei-tion,  below 
root  of  trochanter  major,  the  anterior  inter-tro- 
chantcric  line,  and  posteriorly  to  the  middle  of  the 
neck  of  the  femur.  Behind  the  ligament  is  very 
thin  and  loose. 

Accessory,  or  U'lo-femoml  ligament, — origin,  ante- 
rior inferior  spine  of  ilium.  Insertion,  into  anterior 
inter  trochanteric  line. 

Ligimentum  teres, — origin,  depression  on  head 
of  femur.  Insertion,  by  two  bands  into  the  extremi- 
ties of  the  notch,  and  into  the  transverse  liga- 
ment. 

Cotyloid  ligament,  a  circular  fibro-cartilaginous 
band  attached  to  the  margin  of  the  acetabulum. 

Transverse  ligament,  attached  to  the  opposite 
points  of  the  notch,  converting  it  into  a  foramen 
for  the  passage  of  the  nutrient  vessels  of  the  joint. 

Synovial  membrane,  reflected  from  inside  of  cap- 
sule upon  periosteum  of  neck  and  cartilaginous 
surface  of  head  ;  is  continued  over  ligamentura 
teres,  and  thence  is  reflected  upon  the  cartilaginous 
surface  of  acetabulum. 

Nei-ves,  from  the  obturator,  great  sciatic,  sacral 
plexus,  and  accessory  obturator  if  present. 

KNEE-JOINT. 

Bony  formation,  condyles  of  femur,  head  of  tibia, 
and  the  patella. 


97 

Ligamenium  patellce, — origin^  lower  angle  of  pa- 
tella.    Insertion,  tubercle  of  tibia. 

Posterior  lifjament, — origin,  tendon  of  semi-mem- 
branosus  muscle  at  internal  and  posterior  part  of 
tibia.     Insertion,  external  condyle  of  femur. 

Internal  lateral  ligament, — origin,  internal  con- 
dyle of  femur.  Insertion,  internal  surface  of  tibia 
and  semilunar  cartilage.     It  is  long  and  flat. 

External  lateral  ligament, — origin,  external  con- 
dyle of  femur.  Insertion,  head  of  fibula.  This 
ligament  is  often  divided  into  two  by  the  tendon 
of  the  biceps  muscle.     It  is  short  and  round. 

Synovial  membrane,  lines  the  back  part  of  the 
patella-,  from  Avhich  it  is  reflected  two  or  three 
inches  on  the  fore  part  of  the  femur,  and  on  its  con- 
dyles; from  thence  it  is  conducted  by  the  crucial 
ligaments  to  the  semilunar  cartilages,  and  head  of 
tibia. 

Alar  ligaments,  arise  from  each  side  of  patella, 
and  unite  below  that  bone.  They  arc  mere  folds 
of  synovial  membrane. 

Ligamentum  mucosum, — origin,  fatty  substance 
behind  ligamentum  patellae.  Insertion,  hollow,  be- 
tween the  condyles.  It  is  also  a*  fold  of  synovial 
membrane. 

Coronary  ligaments,  connect  the  circumferences 
of  the  semilunar  cartilages  to  the  tibia. 

Transverse  ligament,  attached  to  the  anterior 
portion  of  each  semilunar  cartilage. 


98 

Anterior  crucial  ligament,  oblique, — origin,  inner 
side  of  external  condyle.  Insertion,  near  the  fore 
part  of  spine  of  tibia,  where  it  is  connected  to  the 
cornu  of  the  internal  semilunar  cartilage. 

Posterior  crucial  ligament,  vertical, — origin,  inner 
side  of  internal  condyle.  Insertion,  depression  on 
back  part  of  head  of  tibia,  and  external  semilunar 
cartilage. 

Semilunar  cartilages,  thick  externally,  thin  inter- 
nally ;  concave  above,  flat  below.  The  outer  con- 
vex edge  of  the  internal  is  attached  to  the  lateral 
ligament ;  the  inner  edge  is  free  ;  the  anterior  and 
posterior  extremities  of  each  are  attached  to  the 
head  of  the  tibia.  The  outer  cartilage  is  circular, 
the  inner  is  semicircular. 

Nerves,  from  the  obturator,  anterior  crural,  ex- 
ternal and  internal  popliteal. 

TIBIO-FIBULAR   ARTICULATION, 

The  head  of  the  fibula  is  attached  to  the  tibia 
by  anterior  and  posterior  Jibrous  bands  and  synovial 
membrane. 

Interosseous  membrane,  extends  from  one  bone  to 
the  other  nearly  the  whole  length. 

The  lower  extremities  of  the  tibia  and  fibula  are 
connected  together  by  anterior  and  posterior  liga- 
ments; the  synovial  membrane  is  a  prolongation  of 
that  which  lines  the  ankle  joint. 


99 


ARTICULATION    OF    THE    ANKLE. 

Bony  formation,  lower  ends  of  tibia,  fibula,  and 
astragalus. 

Internallateral  ligament, — origin,  internal  malle- 
olus. Insertion,  astragalus,  os  calcis,  scaphoid, 
and  calcaneo-scaphoid  ligament. 

External  lateral  ligaments  are  three;  all  take 
their  origin  from  the  external  malleolus.  Insertion 
of  anterior,  upper  and  outer  part  of  astragalus. 
Insei-tion  of  middle,  os  calcis.  Insertion  of  poste- 
rior, ridge  on  the  back  of  astragalus,  which  bounds 
the  groove  for  the  flexor  longus  pollicis. 

Anterior  ligament, — origin,  anterior  edge  of  tibia. 
Insertion,  upper  and  outer  part  of  astragalus. 

The  synovial  membrane  covers  the  opposed  sur- 
faces of  the  bones,  and  sends  upwards  a  prolonga- 
tion into  the  inferior  tibio-fibular  articulation. 

Nerve,  from  the  anterior  tibial. 


ARTICULATION   OF   THE   TARSUS. 

The  astragalus  and  os  calcis  have  two  articular 
surfaces,  covered  by  synovial  membranes. 

Interosseous  ligament,  passes  nearly  perpendicu- 
larly from  the  groove  which  separates  the  inferior 
articular  surfaces  of  the  astragalus,  to  the  corre- 
sponding groove  in  the  os  calcis. 
h2 


100 

Posleiior  ligament,  is  attached  to  the  posterior 
edges  of  the  astragahis  and  os  calcis. 

External  lateral  ligament,  passes  from  the  astra- 
galus to  the  outer  surface  of  the  os  calcis. 

There  are  two  synovial  membranes  :  one  poste- 
rior to  the  interosseous  ligament,  between  the  as- 
tragalus and  OS  calcis ;  a  second  anterior  to  the 
interosseous  ligament,  between  the  astragalus  and 
OS  calcis,  and  continued  foi*wards  between  the 
astragalus  and  scaphoid  bone,  over  the  calcaneo- 
scaphoid  ligament. 

The  bones  of  the  tarsus  are  connected  on  their 
dorsal  and  plantar  aspects  by  numerous  ligament- 
ous bands. 

Calcaneo-scapJioid  ligament, — origin,  inferior  sur- 
face of  OS  calcis.  Insertion,  inferior  surface  of 
scaphoid  bone. 

It  is  composed  of  clastic  tissue^  and  is  supported 
inferiorly  by  the  tendon  of  the  tibialis  posticus 
muscle  ;  superiorly  it  forms  with  the  os  calcis  and 
scaphoid  bone  a  cup,  which  receives  the  head  of 
the  astragalus. 

Calcaneo-cuhoid  ligament, — origin,  posterior  in- 
ferior part  of  OS  calcis.  Insertion,  under  part  of 
cuboid  bone,  and  third  and  fourth  metatarsal  bones. 

The  superficial  fibres,  longer  than  the  deeper, 
form  the  "ligamentum  longum  plantae."  There 
is  a  distinct  synovial  membrane  between  the  calca- 
neum  and  cuboid  bones. 


101 

The  three  cuneiform  bones  are  connecteil  by 
dorsal,  plantar,  and  interosseous  ligaments :  one 
synovial  membrane  is  reflected  over  their  opposed 
surfaces  with  the  scaphoid  bone. 

If  an  oblique  section  be  made  through  the  tarsus 
and  metatarsus,  the  six  synovial  membranes  will 
be  demonstrated.  One  between  the  os  calcis  and 
astragalus,  behind  the  interosseous  ligament;  one 
between  the  same  bones  in  front  of  that  ligament 
and  running  up  between  the  anterior  surface  of 
the  astragalus  and  the  fossa  of  the  scaphoid;  a  third 
between  the  os  calcis  and  the  cuboid  ;  a  fourth  be- 
tween the  cuboid  and  bases  of  the  fourth  and 
fifth  metatarsal  bones  ;  a  fifth  between  the  scaphoid 
and  three  cuneiform  bones,  which  runs  forward 
between  these  bones  and  tiie  bases  of  the  second 
and  third  metatarsal  bones,  and  the  sixth  between 
the  internal  cuneiform  bone  and  the  metatarsal 
bone  of  the  great  toe. 

TARSO-METATARSAL  ARTICULATIONS. 

These  joints  are  secured  by  dorsal  and  plantar 
ligaments,  and  are  lined  by  synovial  membranes. 
The  metatarsal  bones  are  secured  to  the  phalanges, 
and  the  phalanges  to  each  other,  by  lateral  liga- 
ments and  synovial  membranes.  There  is  one 
synovial  membrane  between  the  internal  cuneiform 
bone  and  the  first  metatarsal  bone ;  a  second  be- 


102 

tween  the  os  cuboides  and  the  fourth  and  fifth 
metatarsal  bones.  The  second  and  third  meta- 
tarsal bones  form  part  of  the  articulation  between 
the  cuneiform  and  scaphoid  bones. 


THE    FASCliE.  , 

CERVICAL      FASCIA. 

The  superficial  fascia  is  thin,  and  intimately 
connected  with  the  fibres  of  the  platysma  myoides. 
The  deep  fascia  binds  down  and  invests  the  mus- 
cles of  the  neck.  It  is  a  strong  dense  pearly-white 
structure,  attached  behmd  to  the  spines  of  the  cer- 
vical vertebrae,  in  front  to  the  mesial  line,  and  be- 
low to  the  c'avicle  and  sternum  ;  above  it  is  con- 
nected with  the  jaw  and  parotid  gland;  and  it 
sends  a  process  from  the  styloid  process  to  the 
angle  of  the  jaw,  known  as  the  stylo-maxillary 
ligament.  The  sterno-mastoid,  the  omo-hyoid,  and 
the  subclavius  muscles,  receive  complete  .sheaths  of 
fascia ;  the  sheath  of  the  great  vessels  of  the  neck 
is  strengthened  by  it. 

SUPERFICIAL   FASCIA    OF    THE   ABDOMEN 

Passes  downwards  from  the  thorax  over  the  ab- 
dominal muscles  and  Poupart's  ligament  to  the 
thigh.     In  the  median  line  it  passes  off  the  pubcs 


103 

npon  the  penis,  forming  its  suspensory  li^i^ament, 
and  in  the  female  it  descends  into  the  Libia.  In 
the  male  it  passes  on  each  side  round  the  spermatic 
cord  into  the  scrotum,  and  becomes  continuous  with 
the  fascia  of  the  perineum.  After  having  passed 
over  Poupart's  ligament  it  forms  envelopes  for  the 
inguinal  glands,  and  adheres  to  the  fascia  lata, 
presenting  a  cribriform  appearance  {vide  Fascia 
lata)  ;  and  continuing  its  course  downwards,  be- 
comes identified  with  the  subcutaneous  cellular 
tissue  of  the  lower  extremity. 

FASCIA  TRANSVERSALIS  AND  FASCIA  ILIACA. 

The  fascia  transversaiis  is  placed  between  the 
transvcrsalis  mus{.'le  and  the  peritoneum  ;  it  is 
very  strong  infcriorly,  and  is  connected  to  the 
internal  lip  of  the  ilium  and  to  the  whole  length 
of  Poupart's  ligament,  and  is  continuous,  behind 
the  rectus  muscle,  with  the  fascia  of  the  opposite 
side.  As  the  external  iliac  vessels  are  passing  be- 
neath Poupart's  ligament,  a  prolongation  of  this 
fascia  extends  along  the  anterior  aspect  of  their 
sheath,  and  becomes  identified  with  the  cribriform 
fascia  in  the  groin.  The  spermatic  cord  in  the  male, 
and  the  round  ligament  in  the  female,  pass  through 
a  foramen  in  this  fascia  about  half  an  inch  above 
Poupart's  ligament,  and  midway  between  the  spine 
of  the  ilium  and  the  symphysis  pubis  ;  this  opening 


104 

is  the  internal  abdominal  ring;  from  its  margin 
is  proloni^ccl  over  the  cord  a  funnel-shaped  pro- 
cess, called  the  infundibuUforni  fascia. 

The  fascia  iliaca  is  much  stronger  than  the 
fascia  transversalis ;  it  is  connected  to  the  inner 
lip  of  the  ilium,  passes  over  the  iliacus  internus 
muscle,  adheres  to  Poupart's  ligament,  from  which 
it  passes  behind  the  sheath  of  the  femoral  vessels 
into  the  thigh,  and  is  connected  with  the  capsule 
of  the  hip-joint  and  the  pubic  portion  of  the  fascia 
lata.  The  processes  of  fascia  transversalis  and 
fascia  iliaca,  passing  one  in  front  and  the  other 
behind  the  femoral  vessels,  and  uniting  at  the  outer 
and  inner  border,  form  the  sheath  of  the  vessels. 
The  fascia  propria  of  a  femoral  hernia  is  formed 
by  the  sub-serous  cellular  tissue  of  the  peritoneum 
extended  over  the  upper  opening  of  the  femoral  ring 
(septum  crurale),  and  by  the  sheath  of  the  vessels 
here  described.  The  fascia  iliaca  continued  into 
the  pelvis  is  continuous  with  the  pelvic  fascia  ;  this 
lines  the  parietes  of  this  cavity  as  far  as  the  upper 
origin  of  the  levator  ani  muscle,  where  it  divides 
into  two  layers  ;  one  layer,  the  outer,  called  the 
obturator  fascia,  descends  between  the  obturator 
internus  muscle  and  the  levator  ani,  and  is  attached 
to  the  great  sciatic  ligament,  the  tuberosity  of  the 
ischium,  and  pubes.  The  internal  layer  of  the 
pelvic  fascia,  called  also  recto-vesical  fascia,  passes 
downwards  alon^r  the  inner  surface  of  the  levator 


105 

ani  muscle  to  the  inferior  margin  of  the  symphysis 
pubis,  from  which  it  is  reflected  on  the  prostate 
gland  and  neck  of  the  bladder,  forming  the  anterior 
true  U(jaments  of  the  bladder,  and  laterally  it  is  re- 
flected on  the  sides  of  this  viscus,  forming  its  lateral 
true  U(jaments,  and  another  prolongation  forms  the 
capsule  of  the  vesiculse  seminales. 


SUPERFICIAL  PERIXEAL  FASCIA 

Adheres  to  the  rami  of  the  ischium  and  pubes  of 
either  side,  and  extends  across  the  perineum,  being 
continuous  anteriorly  with  the  superficial  fascia  of 
the  scrotum  derived  from  the  superficial  fascia  of 
the  abdomen. 


TRIANGULAR   LIGAMENT    OF   THE    URETHRA. 

The  triangular  ligament  between  the  rami  of  the 
pubes  is  an  interosseous  ligament,  like  the  mem- 
brane filling  up  the  obturator  foramen  ;  it  is  con- 
nected on  either  side,  to  the  rami  of  the  ischium 
and  pubes,  its  base  looking  towards  the  rectum,  its 
apex  towards  the  subpubic  ligament ;  it  is  pierced 
by  the  membranous  portion  of  the  urethra,  which 
passes  through  the  ligament  about  three-quarters 
of  an  inch  below  the  pubes.  It  consists  of  two  lay- 
ers, between  which  are  situated  the  division  of  the 
pudic  artery,  Cowper's  glands,  and  (he  compressor 


106 

iiretlirce ;  one  layer  [ihe  anterior)  is  expanded  on 
the  bnlb,  keepini^  that  body  in  its  situation  ;  the 
other  {the  posterior)  is  continued  along  the  mem- 
branous portion  of  the  nrethra  to  the  prostate 
gland,  forms  its  capsule,  and  becomes  continuous 
on  the  bladder  with  the  vesical  layer  of  the  fascia 
pelvica.  The  li;:rament  is  sometimes  called  the 
deep  perineal  fascia,  but  this  term  should  properly 
be  applied  to  a  layer  of  fascia  extended  over  the 
deep  muscles  of  the  perineum.  Urine,  when  it 
escapes  from  the  urethra,  lies  under  the  superficial 
fascia,  and  makes  its  way  into  the  scrotum.  It 
cannot  make  its  way  into  the  thi^^h,  on  account  of 
the  attachment  of  the  superficial  fascia  to  the  rami 
of  the  ischia  and  pubes.  The  triangular  lig- 
ament extends  for  a  very  little  distance  below 
the  urethra.  In  the  female  it  is  smaller  than  in 
the  male. 

FASCIA   OF   UPPER   EXTREMITY 

Consists  of  tendinous  fibres,  which  are  stronger 
in  some  situations  than  others;  it  invests  the  en- 
tire arm,  and  sends  partitions  between  the  several 
muscles.  It  takes  its  origin  superiorly  from  the 
spine  of  the  scapula,  adheres  to  the  condyles  of 
the  humerus,  and  to  the  ridges  which  lead  to 
them ;  passes  from  thence  on  the  forearm,  where  it 
is  very  strong,  particularly  at  its  posterior  part, 
and,  binding  down  the  several  muscles,  reaches  the 


107 

wrist-joint,  to  the  angular  ligaments  of  which  it  is 
connected. 

The  palmar  fascia,  of  triangular  form,  is  very 
strong,  and  takes  its  origin  from  the  anterior  an- 
nular ligament;  from  this  it  expands  over  the 
palm,  and  near  the  fingers  divides  into  four  fasci- 
culi, each  of  which  is  forked,  and  inserted  into 
either  side  of  the  sheaths  of  the  flexor  tendons,  and 
into  the  ligaments  of  the  first  phalanges. 

FASCIA   LATA. 

The  fascia  lata  takes  its  origin  from  the  crest  of 
the  ilium,  the  spines  of  the  sacrum,  the  os  coccygis, 
Poupart's  ligament,  the  tuberosity  of  the  ischium, 
and  the  rami  of  the  ischium  and  pubcs.  From  this 
extensive  connexion  it  extends  down  the  thigh, 
confining  the  different  muscles  in  their  situation, 
and  also  sending  partitions  between  them.  At  the 
posterior  part  of  the  thigh  it  adheres  intimately 
to  the  linea  aspera,  and  at  the  knee-joint  to  the 
condyles  of  the  femur  and  the  capsular  ligament ; 
it  is  then  continued  over  the  heads  of  the  tibia  and 
fibula,  to  which  it  adheres,  and  fonns  the  fascia  of 
the  leg. 

Upon  the  anterior  and  upper  part  of  the  thigh, 
the  fascia  lata,  from  its  special  arrangement,  has 
been  divided  into  the  iliac  and  pubic  portions,  and 
about  an  inch  and  a  half  below  Poupart's  ligament, 


108 

and  between  the  iliac  and  pubic  portions,  it  pre- 
sents the  opening  for  the  saphcna  vein.  This 
opening  is  semilunar,  the  concavity  being  directed 
towards  Poupart's  ligament;  it  presents  an  in- 
ternal and  external  cornu,  and  its  edge,  turning 
inwards  on  itself,  becomes  continuous  with  the 
sheath  of  the  femoral  vessels. 

The  puhic  portion  of  the  fascia  lata  covers  the 
pcctineus  muscle,  adheres  to  the  spine  of  the  pubes 
and  the  linea  ilio-pectinea,  passes  behind  the 
sheath  of  the  femoral  vessels,  and  becomes  contin- 
uous with  the  fascia  iliaca. 

The  iliac  portion  of  the  fascia  lata  covers  the 
sartorius,  tensor  vaginae  femoris,  rectus,  and  iliac 
muscles,  and  presents  towards  the  pubic  portion  a 
crescentic  or  falciform  edfje,  the  aspect  of  which  is 
directed  downwards  and  inwards;  the  inferior 
cornu  of  this  edge  is  continuous  with  the  outer 
cornu  of  the  saphenio  opening,  and  its  superior 
cornu  extends  along  Poupart's  ligament,  crosses 
the  femoral  vessels,  and  is  inserted  into  Gimbernat's 
ligament,  and  the  linea  ilio-pectinea;  the  upper 
part  of  the  falciform  edge  is  called  Hoy's  ligament. 

The  cribriform  fascia. —  The  superficial  fascia,  in 
passing  over  Poupart's  ligament  to  the  groin,  ad- 
heres to  the  crescentic  edge  of  the  fascia  lata,  and 
to  the  edge  of  the  saphenous  opening,  and  is  at- 
tached to  that  layer  of  the  fascia  transvcrsalis 
which  passes  anterior  to  the  sheath  of  the  femoral* 


109 

vessels;  this  portion  of  the  superficial  fascia  is 
perforated  by  numerous  small  blood-vessels,  and  by 
the  anterior  superficial  absorbents  of  the  limb, 
which  gives  it,  when  dissected,  a  cribriform  ap- 
pearance, from  which  it  derives  its  name. 

The  fascia  of  the  leg  adheres  to  the  heads  of  the 
tibia  and  fibula,  and  to  the  spine  of  the  tibia,  to 
the  annular  ligaments  of  the  ankle-joint,  and  to  the 
malleoli ;  it  binds  down  the  muscles,  sends  parti- 
tions between  them,  which  pass  from  its  posterior 
surface  to  the  bones  of  the  leg  and  interosseous 
membrane,  and  from  the  anterior  annular  ligament 
it  is  continued  then  upon  the  dorsum  of  the  foot. 

The  plantar  fascia  is  very  strong,  and  arises 
from  the  under  aspect  of  the  os  calcis,  is  attached 
to  the  sides  of  tarsus  and  metatarsus,  and  sends 
two  processes  between  the  muscles  of  the  sole  of 
the  foot  dividing  them  into  an  internal,  a  middle, 
and  an  external  set.  At  the  base  of  the  toes  it 
divides  into  five  portions,  each  of  which  bifurcates, 
and  is  inserted  by  two  fasciculi  into  the  lateral  lig- 
aments of  the  joints,  and  into  the  sheaths  of  the 
flexor  tendons.  This  fascia  is  strengthened  by 
transverse  fibres. 


110 
MUSCLES. 


Occipito-frontalls, — origin,  external  two-thirds  of 
superior  curved  line  of  occipital  bone,  and  pos- 
terior external  part  of  mastoid  process  of  temporal 
bone.  Insertion,  intej^uments  of  eyebrows,  where 
the  fibres  become  blended  with  those  of  the  pyra- 
midalis  nasi,  the  corrugator  supercilii,  and  the 
orbicularis  palpebrarum.  N.  facial  and  sometimes 
also  by  small  occipital. 

MUSCLES    OF    EXTERNAL   EAR. 

AttoUens  aurem. — 0.  aponeurosis  of  occipito- 
frontalis  above  external  ear.  /.  upper  and  ante- 
rior part  of  cartilage  of  ear.     N.  small  occipital. 

Attrahens  aurem. — 0.  lateral  part  of  cranial 
aponeurosis.     7.  anterior  part  of  helix.     N.  facial. 

Pietrahens  aurem. — 0.  mastoid  process.  1.  back 
part  of  concha.     N.  facial. 


Orbicularis  palpebrarum. — 0.  internal  angular 
process  of  frontal  bone  and  upper  edge  of  tendo 
oculi.  It  surrounds  the  orbit.  Z  nasal  process  of 
superior  maxillary  bone  and  inferior  edge  of  tendo 
oculi.     N.  facial. 

Tensor  tarsi. — 0.  edge  of  lachrymal  bone.      /. 


Ill 

tarsal  cartilages  as  far  as  puncta  laclirjmalia. 
N.  facial. 

Corrngator  supercilii. — 0.  superciliary  ridge  of 
frontal  bone.  /.  middle  of  eyebrow,  beneath  or- 
bicularis muscle.'    N.  facial. 

Pyramidalis  nasi — 0.  occipito-fron talis  muscle, 
descends  along  nasal  bones,  I.  compressor  nasi 
muscle.     N.  facial. 

Compressor  jrasi — 0.  canine  fossa  in  superior 
maxilla.     /.  dorsum  of  nose.     N.  facial. 

Levator  lahil  super ioris  alaique  nasi. —  0.  upper 
extremity  of  nasal  process  of  superior  maxilla,  and 
from  edge  of  orbit  above  infra-orbital  foramina. 
/.  side  of  the  ala  of  the  nose  and  upper  lip.  N. 
facial. 

Zf/gomaticus  minor. — 0.  upper  part  of  malar 
bone.  /.  upper  lip,  near  commissure.  Sometimes 
wanting.     N.  facial. 

Zi/gomaficus  major. — 0.  lower  part  of  malar 
bone,  near  zygomatic  suture.  I.  angle  of  mouth. 
N.  facial. 

Levator  anguli  oris. — 0.  canine  fossa  above  alve- 
olus of  first  molar  tooth.  /.  commissure  of  lips, 
and  orbicularis  oris.     N,  facial. 

Levator  lahii  super  ioris. — 0.  orbital  border  of 
superior  maxillary  and  malar  bones.  /.  upper  lip. 
N.  facial. 

Depressor  lahii  super  ioris  alceque  nasi. — 0.  myrti- 
form  fossa  above  canine  and  incisor  teeth  of  supe- 


112 

rior  maxilla.  1.  integuments  of  upper  lip  and  fibro- 
cartilage  of  septum  and  ala  nasi.     N.  facial. 

Depressor  anyuU  oris. — 0.  external  oblique  line 
on  lower  jaw,  extending  from  anterior  edge  of 
masseter  muscle  to  mental  foramen.  1.  commissure 
of  lips.     N,  facial. 

Depressor  lahii  inferioris. —  0.  side  and  front  of 
lower  maxilla,  above  its  base.  I.  half  of  lower  lip 
and  orbicularis  oris.     N.  facial. 

Levator  lahii  inferioris. — 0.  alveoli  of  incisor 
teeth,  lower  jaw.  /.  integuments  of  chin.  N.  facial. 

Orbicular  is  oris,  surrounds  mouth  by  two  fleshy 
fasciculi.     N.  facial. 

Dilatator  naris  posterior.  —  0.  from  margin  of 
nasal  notch  of  superior  maxilla.  /.  skin  of  margin 
of  nostril.     N.  facial. 

Dilatator  naris  anterior. — 0.  cartilage  of  ala  of 
nostril.     I.  margins  of  nostril.     N.  facial. 

Compressor  nariiim  minor. — 0.  cartilage  of  ala. 
/.  skin  of  tip  of  nose.     N.  facial. 

Buccinator. — 0.  three  last  alveoli  of  superior 
maxilla  and  external  surfiice  of  posterior  alveoli 
of  lower  maxilla,  and  from  a  ligament  (pterygo- 
maxillary)  which  extends  from  the  hamular  pro- 
cess of  the  sphenoid  bone  to  the  extremity  of  the 
mylo-hyoid  ridge  of  the  inferior  maxilla.  /.  com- 
missure of  lips.     N.  facial. 

Risorius. — 0.  facia  over  masseter.  L  angle  of 
mouth.     N.  facial. 


113 


MUSCLES    OF    LOWER  JAW. 

MasseteVy  consists  of  two  portions :  Anterior 
portion^  0.  superior  maxilla,  where  it  joins  malar 
bone,  and  inferior  edge  of  latter.  I.  outer  surface 
of  angle  of  lower  jaw.  Posterior  portion^  0.  edge 
of  malar  bone  and  zygomatic  arch,  as  far  as  gle- 
noid cavity.  /.  ramus  of  lower  jaw,  and  coronoid 
process.     N.  inferior  maxillary. 

Temporal. — 0.  side  of  cranium,  beneath  semi- 
circular ridge  on  parietal  bone,  temporal  fossa,  and 
aponeurosis.  /.  coronoid  process  of  inferior  max- 
ilia  to  last  molar  tooth.     N.  inferior  maxillary. 

Pterygoideus  interims. — 0.  inner  side  of  external 
pteiygoid  plate  and  tuberosity  of  palate  bone.  1. 
inner  side  of  angle  of  jaw  and  rough  surface  above. 
N.  inferior  maxillary. 

Pterygoideus  externus. — 0.  outer  side  of  external 
pterygoid  plate,  crest  on  great  ala  of  sphenoid  bone 
and  tuberosity  of  superior  maxilla.  L  anterior 
and  internal  part  of  neck  of  lower  jaw,  inter-articu- 
lar cartilage,  and  inferior  synovial  membrane.  N, 
inferior  maxillary. 

MUSCLES  OF  ANTERIOR  AND  LATERAL  PARTS 
OF  NECK. 

Platysma  myoides. — 0.  fascia  covering  upper 
and  outer  part  of  deltoid,  great  pectoral,  and  tra- 

I 


114 

pezins  muscles.  I.  chin,  lower  jaw,  and  fascia 
covering  parotid  gland.  Some  of  the  fibres  become 
blended  with  those  of  the  depressor  labii  inferioris 
and  anguli  oris.  N.  facial  and  superficial  cer- 
vical. 

Sterno-cleido  masioideus. — 0.  upper  and  anterior 
part  of  first  bone  of  sternum  and  sternal  third 
sometimes  half,  of  clavicle.  I.  upper  part  of  mas- 
toid process  and  external  third  of  superior  curved 
line  of  occipital  bone.  N.  spinal  accessory  and 
cervical  plexus. 

Sterno-hyoideus. — 0.  posterior  surface  of  first 
bone  of  sternum,  cartilage  of  first  rib,  sternal  end 
of  clavicle  and  stemo-clavicular  ligament.  I.  lower 
border  of  body  of  os  hyoides.  N.  descendens 
noni. 

Sterno-thyroideus. — 0,  posterior  surface  of  first 
bone  of  sternum  and  cartilage  of  first  rib.  i. 
oblique  line  on  ala  of  thyroid  cartilage.  It  is 
broader  than  the  preceding.  N,  descendens 
noni. 

Omo-hjoideus. — 0.  behind  transverse  notch  in 
scapula,  from  the  ligament  which  passes  over  the 
notch.  1.  lower  border  of  os  hyoides,  at  the  junc- 
tion of  its  body  and  great  comu.  It  is  a  double- 
bellied  muscle,  the  mesial  tendon  being  bound 
down  by  a  pulley  of  cervical  fascia.  N.  descendens 
noni. 

Digastricus, — A  double-bellied  muscle.     Poste 


115 

rior  belly,  0.  groove  internal  to  mastoid  process. 
Anterior  belly,  0.  rough  depression  on  inner  sur- 
face of  base  of  jaw  near  its  symphysis.  The 
two  bellies  unite,  at  an  angle,  in  a  tendon  which 
passes  through  the  fibres  of  the  stylo- hyoid  muscle, 
and  is  attached  to  the  os  hyoides  by  aponeurosis. 
N.  anterior  belly  by  mylo-hyoidean,  posterior  belly 
by  facial. 

Mi/Io-hyotdeus. — 0.  mylo-hyoid  ridge  of  inferior 
maxilla.  L  base  of  os  hyoides,  and  middle  tendi- 
nous raphe'  common  to  it  and  its  fellow.  N.  mylo- 
hyoidean. 

Genio-hi/oideus.  —  0.  inner  side  of  symphysis  of 
lower  maxilla  above  digastricus.  I.  base  of  hyoid 
bone.     N.  hypoglossal. 

Hyo-glossus. — 0.  greater  and  lesser  cornua,  and 
part  of  body  of  os  hyoides.  L  side  of  tongue. 
This  muscle  is  sometimes  described  as  three,  the 
basio-glossus,  cerato-glossus,  and  chondro-glossus. 
N.  hypoglossal. 

Genio-hyo-glossus. — 0.  superior  genial  tubercle 
on  symphysis.  1.  mesial  line  of  tongue  from  apex 
to  base,  and  body  and  lesser  cornu  of  hyoid  bone. 
N.  hypoglossal. 

Lingualis,  consists  of  fasciculi  of  fibres  running 
from  apex  to  base  of  tongue,  and  lying  between  the 
genio-hyo-glossus  and  the  hyo-glossus.  N.  hypo- 
glossal and  chorda  tympani. 

Stylo-hyoideus. — 0.  outer  side  of  styloid  process 
I  2 


116 

near  its  middle.  1.  cornu  and  body  of  os  liyoides. 
N.  facial. 

Sti/Io-glosstis. — 0.  styloid  process,  near  its  tip 
and  the  stylo-maxillary  ligament.  I.  side  of  tongue, 
as  far  as  the  tip.     N.  hypoglossal. 

Stylo-pharyngeus. — 0.  inner  part  of  base  of 
styloid  process,  i.  side  of  pharynx,  and  posterior 
border  of  thyroid  cartilage.  N.  glosso-pharyn- 
geal. 

MUSCLES    OF    THE    PHARYNX. 

Inferior  constrictor. —  0.  side  of  cricoid  carti- 
lage, inferior  cornu,  and  posterior  part  of  ala  of 
thyroid  cartilage,  i.  with  its  fellow,  in  the  median 
raphd  on  back  of  pharynx. 

Middle  constrictor.  —  0.  greater  and  lesser 
cornua  of  os  hyoides  and  stylo-hyoid  ligament. 
J.  median  raphe  Und  basilar  process  of  occipi  tal 
vbone-^ 

Superior  constrictor. —  0.  hamular  process  and 
lower  border  of  internal  pterygoid  plate ;  pterygo- 
maxillary  ligament,  tuberosity  of  palate  bone,  re- 
flected tendon  of  tensor  palati,  »tdeof  tongue  and 
posterior  third  of  mylo-hyoid  ridge.  I.  basilar 
process  of  occipital  bone  and  median  raphe  of 
pharanx.  ' 

These  muscles  are  supplied  by  the  pharyngeal 
plexus,  and  external  laryngeal  nerve. 


117 

MUSCLES   OF    THE    PALATE. 

Levator  palati — 0.  petrous  portion  of  temporal 
bone  in  front  of  carotid  foramen,  and  from  carti- 
lage of  Eustachian  tube.  /.  broadly  into  soft 
palate.  N.  facial  nerve  through  petrosal  branches. 

Tensor,  vel  clrcumjlexus  ■palati. —  0.  scaphoid 
fossa  of  splienoid,  and  front  part  of  Eustachian 
tube;  tendon  winds  round  Iiamular  process.  I. 
into  hard  palate  and  velum,  meeting  its  fellow  in 
middle  line.     iV.  from  otic  ganglion. 

Azijrjos  uvulce. — 0.  posterior  nasal  spine  of  pa- 
late.    7.  into  uvula.     N.  from  petrosal  nerves. 

Palatoglossus. — 0.  inferior  surface  of  soft  pa- 
late. /.  side  of  tongue.   N.  from  Mecksrs  ganglion. 

Palato-pharyngeus. — 0.  inferior  surface  of  soft 
palate.  /.  side  and  back  of  pharynx,  and  side  of 
thyroid  cartilage.     N.  from  Meckel's  ganglion. 


Thi/rohyoideus. — 0.  oblique  ridge  on  ala  of  thy- 
roid carliiage.  I.  lower  border  of  great  cornu,  and 
body  of  OS  hyoides.     N.  hypoglossal. 

Cricothyroideus. — 0.  fore  part  of  cricoid  carti- 
lage. /.  lower  border  of  thyroid  cartilage.  N, 
external  laryngeal. 

Thyro-arytenoideus. — 0.  posterior  surface  of  thy- 
roid cartilage  near  its  angle.  1.  anterior  edge  of 
arytenoid  cartilage.     N.  inferior  laryngeal. 


118 

Crlco-arytenoideus  lateralis. — 0.  upper  edge  of 
side  of  cricoid  cartilage.  I.  base  of  arytenoid  car- 
tilage.    N.  inferior  laryngeal. 

Crico-art/tenoideus  posticus. — 0.  depression  on 
posterior  surface  of  cricoid  cartilage.  /.  outer  side 
of  base  of  arytenoid  cartilage.  N.  inferior  laryn- 
geal. 

Anjienoideus,  ^l\s  the  interval  between  arytenoid 
cartilages,  and  consists  of  two  arrangements  of 
fibres :  oblique,  run  from  apex  of  one  cartilage  to 
base  of  opposite  one;  transverse,  are  attached  to 
posterior  surface  of  each  cartilage.  N.  inferior 
laryngeal. 

DEEP  MUSCLES  ON  ANTERIOR  AND  LATERAL 
PARTS  OF  THE  NECK. 

Longus  colli. — Divided  into  three  portions — ver- 
tical and  two  oblique.  Vertical  portion  : — 0.  bo- 
dies of  three  upper  dorsal,  and  four  lower  cervical 
and  inter-vertebral  fibro-cartilages.  /.  bodies  of 
second,  third,  and  fourth  cervical  vertebrae.  Supe- 
rior oblique  portion: — 0.  anterior  tubercles  of 
transverse  processes  of  third,  fourth,  and  fifth  cer- 
vical vertebrae.  /.  anterior  tubercle  of  atlas.  In- 
ferior oblique  portion : — 0.  bodies  of  two  upper 
dorsal.  I.  transverse  process  s  of  fifth  and  sixth 
cen'ical  vertebrae.     N.  cervical  plexus. 

Rectus  capitis  anticus  major. — 0.  anterior  tu- 
bercles of  transverse  processes  of  third,  fourth,  fifth, 


119 

and  sixth  cervical  vertebrse.  1.  basilar  process  of 
occipital  bone.     N.  cemcal  plexus. 

Rectus  capitis  antlcus  minor. —  0.  transverse 
process  of  atlas.  /.  basilar  process  of  occipital 
Lone.     N.  cervical  plexus. 

Rectus  capitis  lateralis. — 0.  transverse  process 
of  atlas.  I.  jugular  process  of  occipital  bone.  N. 
sub-occipital. 

Scalenus  anticus.—O.  anterior  tubercles  of  trans- 
verse processes  of  third,  fourth,  fifth,  and  sixth 
cervical  vertebrse.  /.  upper  surface  of  first  rib 
between  its  two  grooves.  N.  lower  cervical 
nerves. 

Scalenus  medius.—O.  posterior  tubercles  of 
transverse  processes  of  six  lower  cervical  vertebrae. 
J.  first  rib,  behind  groove  for  subclavian  artery. 
N.  lower  cervical  nenTS. 

Scalenus  posticus.— 0.  posterior  tubercles  of  trans- 
verse processes  of  two  or  three  lower  cervical  ver- 
tebrie.  1.  upper  edge  of  second  rib  between  its 
tubercle  and  angle.    N,  lower  cervical  nerves. 

THORAX. 

Pectoralis  major.— 0.  sternal  half  of  clavicle, 
anterior  surface  of  sternum,  cartilages  of  all  the 
true  ribs  except  first,  and  aponeurosis  common  to  it 
and  external  oblique  muscle.  /.  by  a  flat  tendon 
into  anterior  edge  of  bicipital  groove,  and  by  an 


120 

aponeurosis  into  fascia  of  forearm,  and  sends  up 
an  expansion  to  the  head  of  the  humsrus,  over  the 
bicipital  groove.    N.  external  anterior  thoracic, 

Pectoralis  minor. — 0,  third,  fourth,  and  fifth 
ribs,  external  to  their  costal  cartilages,  and  from 
an  aponeurosis  over  the  intercostal  muscles.  /. 
inner  and  upper  surface  of  coracoid  process  of  sca- 
pula.    N.  internal  anterior  thoracic. 

Suhclavlus. — 0.  cartilage  of  first  rib.  /.  groove 
on  inferior  surface  of  clavicle.  N.  from  fifth  and 
sixth  cervical. 

Serratus  magnus. — 0.  by  nine  fleshy  slips,  from 
eight  or  nine  superior  ribs.  /.  base  of  scapula, 
N.  posterior  thoracic  nerve. 

Intercostales  are  twenty-two  in  number  on  each 
side  :  eleven  internal  and  eleven  external.  The 
fibres  of  the  external  pass  obliquely  from  behind, 
forwards  and  downwards ;  those  of  the  internal  in 
the  opposite  direction.     N.  intercostals. 

External. — 0.  inferior  edge  of  each  rib,  commen- 
cing at  transverse  processes  of  vertebrae.  /.  ex- 
ternal lip  of  superior  edge  of  rib  beneath,  extend- 
ing to  behind  costal  extremities  of  cartilages. 

Internal. — 0.  at  sternum  from  the  inner  lip  of 
lower  edge  of  each  cartilage  and  rib  as  far  as 
angle.  1.  inner  lip  of  superior  edge  of  cartilage 
and  rib  beneath. 

Levatores  costarum. — 0.  extremity  of  each  dorsal 
transverse  process.     /.  upper  edge  of  rib  below, 


121 

between  tubercle  and  angle.    N.  posterior  divisions 
of  dorsal  nerves. 

Trianrjularis  sterni. —  0.  posterior  surface  and 
edge  of  lower  part  of  sternum  and  ensiform  carti- 
lage. 1.  cartilages  of  second,  third,  fourth,  and 
fifth  ribs.     N.  intercostals. 


MUSCLES    OF    THE    BACK. 

First  Layer, 

Trapezius. — 0.  internal  third  of  superior  curved 
line  of  occipital  bone,  ligaraentura  nucha3,  and 
spinous  processes  of  last  cervical  and  all  dorsal 
vertebras.  /.  posterior  border  of  external  third  of 
clavicle,  acromion  process,  and  superior  edge  of 
spine  of  scapula.  N,  spinal  accessory  and  cervical 
plexus. 

Latissbnus  dorsi — 0.  six  inferior  dorsal  spines, 
and  by  lumbar  fascia  from  all  lumbar  spines,  from 
back  of  sacrum,  posterior  third  of  crest  of  ilium, 
and  from  three  to  four  inferior  ribs.  /.  into  bici- 
pital groove  of  humerus.     N.  subscapular. 

Second  Layer. 

Bhomholdeus  minor. — 0.  lower  part  of  ligamen- 
tum  nuchai  and  spinous  processes  of  last  cervical 
and  first  dorsal.  /.  base  of  scapula,  opposite  to  its 
spine.     N.  fifth  cervical. 


122 

Rhomhoideus  major. —  0.  four  or  five  superior 
dorsal  spines.  /.  base  of  scapula  from  spine  to 
inferior  angle.    N.  fifth  cei-vical. 

Levator  aiifjuU  scapulcB. — 0.  posterior  tubercles 
of  transverse  processes  of  four  superior  cervical 
vertebrae.  /.  base  of  scapula,  between  spine  and 
superior  angle.     N.  cervical  plexus. 

Third  Layer. 

Se7Tatus  posticus  superior.  —  0.  ligament ura 
nucha},  and  two  or  three  dorsal  spines.  J.  second, 
third,  and  fourth,  and  fifth  ribs,  external  to  angles. 
N.  posterior  division  of  cervical  nerves. 

Seiratus  posticus  inferior.  —  0.  two  last  dorsal 
and  two  superior  lumbar  spines.  /.  lower  edges 
of  four  inferior  ribs  anterior  to  angles.  N.  external 
branches  of  dorsal  nerves. 

Splenius  muscle,  flat  and  oblique,  single  at  its 
origin  ;  divides  at  its  insertion  into  two  portions, 
tile  splenius  colli  and  splenius  capitis ;  the  former 
attached  to  the  cervical  vertebraj,  the  latter  to  the 
cranium.  0.  from  spines  of  five  superior  dorsal 
and  last  cervical  vertebrae,  and  from  ligamentum 
nuchae  as  high  as  the  third  cervical  vertebra.  I, 
the  lower  portion,  splenius  colli,  the  smaller,  into 
posterior  tubercles  of  transverse  processes  of  three 
or  four  superior  cenacal  vertebrae.  Upper  portion, 
splenius  capitis,  into  posterior  part  of  mastoid  pro- 


■ 


123 

cess,  superior  curved  ridge  of  occipital  bone,  and 
the  rough  surface  below  it.  N,  posterior  divisions 
of  cervical  nerves. 

Fourth  Layer, 

The  following  muscles  lie  beneath  the  serrati, 
and  a  fascia  called  the  vertebral  aponeurosis.  The 
fleshy  mass  occupying  the  vertebral  grooves  of 
either  side  is  called  erector  spinaj,  and  it  divides 
opposite  the  last  rib  into  two  portions,  sacro-lum- 
balis,  and  longissimus  dorsi. 

Erector  spince. — 0.  from  a  dense  fascia  connected 
with  the  spines  of  the  sacrum,  from  the  posterior 
third  of  the  crista  of  the  ilium,  from  the  posterior 
surface  of  the  sacrum,  and  from  the  great  sacro- 
sciatic  ligament.  The  outer  portion,  called  the 
sacro-lumbalis,  is  inserted  into  the  angles  of  six  or 
seven  lower  ribs.  Musculus  accessorius  ad  sacra- 
lumbalem,  a  continuation  of  sacro-lumbalis.  0. 
angles  of  six  or  seven  lower  ribs,  internal  to  the 
tendons  of  preceding  muscle.  /.  angles  of  six 
upper  ribs,  and  into  transverse  process  of  last  cer- 
vical vertebra.    N.  dorsal  and  lumbar  nerves. 

Cervicalis  ascendens,  the  continuation  of  acces- 
sorius into  the  neck.  0.  from  angles  of  second, 
third,  fourth  or  fifth  upper  ribs.  I.  transverse  pro- 
cesses of  fourth,  fifth,  and  sixth  cervical  vertebra). 

The  inner  portion  of  erector  spina),  lonrjissimus 
dorsi,  is  inserted  into  transverse  processes  of  all 


124 

the  dorsal  and  lumbar  vertebrae,  and  into  all  tlie 
ribs  between  their  tubercles  and  angles.  Trans- 
versalis  colli,  a  continuation  of  the  longissimus 
dorsi.  0.  transverse  process  of  third,  fourth, 
fifth,  and  sixth  dorsal  vertebras.  /.  posterior 
tubercle  of  transverse  processes  of  second,  third, 
fourth,  fifth,  and  sixth  cervical  vertebrse.  N.  dor- 
sal and  lumbar  nerves. 

Traclielo  mastoid,  the  prolongation  of  the  longis- 
simus dorsi  to  the  head.  0.  transverse  processes 
of  four  upper  dorsal,  and  four  lower  cervical  ver- 
tebras. /.  posterior  margin  of  mastoid  process.  N, 
posterior  branches  of  cervical  nerves. 

Complexus. — 0.  transverse  and  articular  por- 
cesses  of  three  or  four  inferior  cervical  and  three 
or  four  superior  dorsal  vertebrae.  /.  occipital  bone, 
between  its  two  transverse  ridges.  N".  posterior 
branches  of  the  cervical  nerves. 

Spinalis  dorsi. — 0.  spinous  processes  of  two 
tipper  lumbar  and  two  last  dorsal.  /.  spinous  pro- 
cesses of  six  or  eight  upper  dorsal.  N.  posterior 
branches  of  the  cervical  nerves. 

Spinalis  colli  —  0.  spinous  processes  of  three 
lower  cervical.  /.  spinous  process  of  axis.  iV. 
posterior  branches  of  the  ceiTical  nerves. 

Fijth  Layer. 
Semi-spinalis  colli. — 0.  extremities  of  transverse 
processes  of  five  or  six  superior  dorsal  vertebrae.    J, 


I 


125 

by  four  heads  into  spines  of  second,  thir.l,  fourth, 
and  fifth  cervical  vertebruB.  N.  posterior  branches 
of  cervical  nerves. 

Semi-spinalis  dorsL — 0.  by  five  or  six  tendons, 
from  transverse  processes  of  dorsal  vertebra?,  from 
fifth  to  eleventh.  /.  extremity  of  spines  of  two  in- 
ferior cervical  and  three  or  four  superior  dorsal 
vertcbrse.     N.  posterior  divisions  of  dnrsal  nerves. 

Multijidus  Spince. — N.  first  fasciculus  arises  from 
spine  of  vertebra  dentata,  and  is  inserted  into  trans- 
verse process  of  third,  each  successively  in  a  similar 
manner  down  to  the  last,  which  arises  from  the 
spine  of  last  lumbar  vertebra,  and  is  inserted  into 
transverse  process  of  sacrum.  iV,  posterior  divi- 
sions of  sacral,  lumbar,  dorsal,  and  cervical 
nerves. 

Rotatores  splnce,  eleven  in  number  on  each  side  ; 
in  the  dorsal  region.  0.  back  part  of  transverse 
process.  /.  into  the  lamina  of  the  vertebra  above. 
N,  dorsal  nerves. 

Inter -spinales,  are  situated  between  spinous 
processes  of  vertebras :  they  are  in  pairs  in  the 
cirvical  region,  iV".  posterior  branches  of  spinal 
nerves. 

Inter-transversales,  attached  and  situated  as  their 
name  implies.  N.  posterior  branches  of  spinal 
nerves. 

Rectus  capitis  posticus  major. — 0.  spinous  pro- 
cess of   second  vertebra,     /.  inferior   transverse 


126 

ridge  of  os  occipitis.  N.  sub-occipital  and  great 
occipital  neiTes. 

Rectus  capitis  posticus  minor.  —  0.  posterior 
tubercle  of  atlas.  /.  occipital  bone,  behind  foramen 
magnum.     N.  sub-occipital. 

OhUquus  inferior. — 0.  spinous  process  of  second 
vertebra.  /.  extremity  of  transverse  process  of 
atlas.     N.  sub-occipital. 

OhUquus  superior. — 0.  upper  part  of  transverse 
process  of  atlas.  I.  occipital  bone,  between  its 
transverse  ridges,  posterior  to  mastoid  process.  N. 
sub-occipital. 

UPPER  EXTREMITY. 

Deltoideus. — 0.  lower  edge  of  spine  of  scapula, 
anterior  edge  of  acromion,  and  external  third  of 
clavicle.  /.  rough  surface  on  outer  side  of  hu- 
merus, near  its  centre     iV^.  circumflex. 

Supra  spinatus. — 0.  all  scapula  above  the  spine, 
which  forms  supra  spinous  fossa,  and  from  fliscia 
covering  muscle.  /.  upper  and  fore  part  of  great 
tuberosity  of  humerus.    ]V.  supra-scapular. 

Infra  spinatus. —  0.  inferior  surface  of  spine  and 
dorsum  of  scapula  beneath,  except  near  the  neck, 
SLS  low  down  as  posterior  ridge  on  inferior  costa.  J. 
middle  of  great  tuberosity  of  humerus.  N.  supra- 
scapular. 

Teres  minor.  —  0.  depression  between  the  two 
ridges  on  inferior  costa  of  scapula,   from  fascia 


127 

covering  it,  and  ligamentous  septa.  I.  inferior 
depression  on  great  tuberosity  of  humerus.  N, 
circumflex. 

Subscapular  is, — 0.  all  the  surface  and  circum- 
ference of  subscapular  fossa.  /.  lesser  tubercle  of 
humerus,  and  a  small  portion  of  the  neck  of  the 
bone.    N.  short  subscapular. 

Teres  major. — 0.  rough  surface  on  inferior  angle 
of  scapula,  below  infra-spinatus.  /.  posterior  edge 
of  bicipital  groove.     N,  middle  subscapular. 

Coraco  brachialis. — 0.  coracoid  process  and  ten- 
don of  short  head  of  biceps.  I.  internal  side  of 
humerus  about  its  middle,  and,  by  an  aponeurosis, 
into  ridge  leading  to  internal  condyle.  N.  muscu- 
lo-cutaneous. 

Biceps. — 0.  short  head,  from  coracoid  process; 
long  head,  from  upper  edge  of  glenoid  cavity.  /. 
back  part  of  tubercle  of  radius.  N.  musculo- 
cutaneous. 

Brachialis  anlicus. — 0.  centre  of  humerus  by 
two  slips  on  either  side  of  insertion  of  deltoid,  and 
fore  part  of  humerus  to  its  condyles.  /.  coronoid 
process  of  ulna  and  rough  surface  beneath.  N, 
musculo-cutaneous  and  musculo-spiral. 

Triceps  extensor  cuhiti. — 0.  long  head,  from 
lower  part  of  neck  of  scapula  and  inferior  costa. 
Second  head,  from  ridge  on  humerus,  below  inser- 
tion of  teres  minor.  Third  head,  from  ridge  below 
insertion  of  teres  major,  leading  to  the  internal 


128 

condyle,  and  from  internal  intermuscular  septum. 
I.  olecranon  process  of  ulna,  and  fascia  of  forearm. 
N,  musculo-spiral. 

Suhanconeus. — 0.  few  fleshy  fibres  from  humerus 
above  olecranon  fossa.  /.  posterior  ligament  of 
elbow.    N.  musculo-spinal. 

Forearm  and  Hand. 

Pronator  radii  teres. — 0.  anterior  part  of  inter- 
nal condyle,  fascia  of  forearm,  inter-muscular 
septa,  and,  by  a  small  slip,  separated  from  the 
larger  head  by  the  median  neiTc,  from  coronoid 
process  of  ulna,  /.  outer  and  back  part  of  radius, 
about  its  centre.    N.  median. 

Flexor  carpi  radialis. — 0.  inner  condyle  and 
inter-muscular  septa.  /.  base  of  metacarpal  bone 
of  index  finger.   N.  median. 

Palmaris  longus. — 0,  inner  condyle  and  fascia 
of  forearm,  and  inter-muscular  septa.  /.  annular 
ligament  and  palmar  aponeurosis,  near  root  of 
thumb.     N.  median. 

Flexor  carpi  ulnar  is. — 0.  inner  condyle,  inner 
side  of  olecranon,  a  tendinous  band  between  these 
points,  under  v^^hich  passes  the  ulnar  nerve,  inner 
edge  of  nearly  whole  length  of  ulna,  and  fascia  of 
forearm.  I.  os  pisiforme  and  base  of  fifth  meta- 
carpal bone.    N.  ulnar. 

Flexor   digitorum   suhlimis. — 0.  inner  condyle, 


L 


129 

internal  lateral  ligament,  coronoid  process,  and 
radius  below  tubercle.  /.  anterior  part  of  second 
phalanges  of  each  finger.   N.  median. 

Flexor  digitorum  profundus.  —  0.  upper  three- 
fourths  of  anterior  surface  of  ulna  by  two  heads, 
which  embrace  the  insertion  of  the  brachialis 
anticus,  internal  half  of  interosseous  ligament,  and 
from  an  aponeurosis  attached  to  tlie  posterior 
border  of  ulna.  /.  last  phalanx  of  each  finger. 
N.  ulnar  and  anterior  interosseous. 

Flexor  longus  pollicis. — 0.  fore  part  of  radius 
below  the  tubercle,  from  interosseous  membrane  to 
within  two  inches  of  carpus,  and  from  coronoid 
process.  /.  last  phalanx  of  thumb.  N.  anterior 
interosseous. 

Pronator  quadratus. — 0.  inferior  fifth  of  anterior 
surface  of  ulna.  I.  anterior  part  of  inferior  fourth 
of  radius.    N.  anterior  interosseous. 

Supinator  radii  longus. —  0.  external  ridge  of 
humerus,  to  within  two  inches  of  outer  condyle,  and 
from  inter-muscular  septum.  I.  rough  surface  on 
the  outside  of  radius,  near  its  styloid  process.  N. 
musculo-spiral. 

Extensor  carpi  radialis  long i or. — 0.  ridge  of 
humerus,  between  supinator  longus  and  external 
condyle.  /.  dorsal  aspect  of  carpal  end  of  meta- 
carpal bone  of  index  finger.     N.  musculo-spiral. 

Extensor  carpi  radialis  brevior. — 0.  inferior  and 
posterior  part  of  external  condyle,  external  lateral 
K 


130 

ligament,  and  inter-raiiscular  septa.  /.  carpal  end 
of  third  metacarpal  bone.  N.  posterior  inter- 
osseous. 

Extensor  d'lgitorwn  comviunis.  '■ —  0.  external 
condyle,  fascia  of  forearm  and  its  inter-muscular 
septa.  /.  posterior  aspect  of  the  second  and  third 
phalanges  of  four  fingers.  N.  posterior  inter- 
osseous. 

Extensor  minimi  digiti. — 0.  in  common  with,  and 
between  extensor  digitonim  communis  and  extensor 
carpi  ulnaris.  /.  posterior  part  of  phalanges  of  little 
finger.     N.  posterior  interosseous. 

Extensor  carpi  ulnaris. —  0.  external  condyle, 
fascia,  and  septa,  and  middle  third  of  uhia.  /.  car- 
pal end  of  the  fifth  metacarpal  bone.  N.  posterior 
interosseous. 

Anconeus. — 0,  posterior  and  inferior  part  of  ex- 
ternal condyle  and  lateral  ligament.  /.  external 
surface  of  olecranon,  and  superior  fifth  of  posterior 
surface  of  ulna.     N.  musculo-spiral. 

Supinator  radii  brevis. — 0.  external  condyle,  ex- 
ternal lateral,  and  orbicular  ligaments,  and  from  a 
ridge  on  oiHtcr  side  of  ulna,  which  commences  be- 
low its  lesser  sigmoid  cavity.  I.  upper  third  of 
external  and  anterior  surface  of  radius,  from  above 
its  tubercle  to  the  insertion  of  pronator  radii  teres. 
N.  posterior  interosseous. 

Eortensor  ossis  metacarpi  poUicis,  lies  immediate- 
ly below  the  border  of  the  supinator  radii  brevis. 


131 

0,  middle  of  posterior  part  of  ulna,  interosseous 
membrane,  and  posterior  surface  of  radius.  /. 
base  of  metacarpal  bone  of  thumb.  N.  posterioT 
interosseous. 

Extensor  primi  internodil  poUicis.—O ,  interos- 
seous membrane,  radius,  and  occasionally  a  small 
portion  of  the  ulna.  /.  base  of  first  j^halanx  of 
thumb.     JW  posterior  interosseous. 

Extensor  secundl  internod'd  j^ollicis. — 0.  poste- 
rior surface  of  ulna,  above  its  centre,  and  from  in- 
terosseous membrane.  /.  base  of  last  phalanx  of 
thumb.   N.  posterior  interosseous. 

Extensor  indicis. — 0.  middle  of  posterior  sur- 
face of  ulna,  and  interosseous  membrane.  /.  second 
and  third  phalanges  of  index  finger,  uniting  with 
the  tendon  of  the  common  extensor.  N.  posterior 
interosseous. 

Abductor  pollicis. — 0.  anterior  surface  of  annu- 
lar ligament  and  os  trapezium.  /.  outside  of 
base  of  first  phalanx,  and  by  an  expansion  into 
both  phalanges.     N.  median. 

Oppovens  pollicis. — 0.  annular  ligament  and  os 
trapezium.  /.  metacarpal  bone  of  thumb.  N. 
median. 

Flexor  pollicis  hrevis. — 0.  external  head,  from 
inside  of  annular  ligament  and  trapezium  and 
sheath  of  the  flexor  carpi  radialis.  /.  external 
sesamoid  bone  and  base  of  first  phalanx  of  thumb. 
Internal  head:    0.  from  ostrapezoides,  os  magnum 


132 

and  base  of  metacarpal  bone  of  middle  finger.  J. 
internal  sesamoid  bone  and  base  of  first  phalanx. 
N.  median  and  ulnar. 

Adductor  pollicis. — 0.  three-fourths  of  anterior 
surface  of  the  third  metacarpal  bone.  /.  inner 
side  of  base  of  first  phalanx  of  thumb.     N.  ulnar. 

Abductor  indkis. — 0.  metacarpal  bone  of  fore- 
finger, and  one-half  of  that  of  the  thumb.  /. 
outer  side  of  base  of  first  phalanx.  The  radial 
artery  passes  between  its  two  heads.  This  is  also 
called  the  first  dorsal  interosseous  muscle.  N.  ulnar. 

Lumhr kales. — Four  in  number.  0.  radial  side 
of  the  tendons  of  flexor  profundus,  near  the  car- 
pus, a  little  beyond  annular  ligament.  /.  mid- 
dle of  first  phalanx  into  tendinous  expansion 
covering  the  back  of  each  finger.  N.  median  and 
ulnar. 

Palmaris  hrevis,  lies  between  the  skin  and  tlie 
palmar  fascia.  0.  annular  ligament  and  palmar 
fascia.  7.  integument  on  inner  side  of  palm.  N, 
ulnar. 

Abductor  minimi  digiti. — 0.  annular  ligament 
and  OS  pisiforme.  I.  ulnar  side  of  first  phalanx. 
N.  ulnar. 

Flexor  brevis  minimi  digiti. — 0.  annular  liga- 
ment and  unciform  bone.  /.  base  of  first  phalanx 
of  little  finger.     N.  ulnar. 

Opponens  minimi  digiti. — Internal  to  last,  and 
overlapped  by  it.     0.  unciform  bone  and  annular 


133 

ligament.  /.  all  the  metacarpal  bone  of  little 
finger.    N.  ulnar. 

Tnterossei  palmares,  three  in  number,  are  ad- 
ductors towards  the  middle  finger.  0.  sides  of 
metacarpal  bones.  iV.  first  phalanges  and  tendi- 
nous expansion  covering  the  dorsum  of  each 
finger. 

1st,  arises  from  ulnar  side  of  second  metacarpal 
bone  ;  2nd,  arises  from  radial  side  of  fourth  meta- 
carpal bone ;  3rd,  arises  from  radial  side  of  fifth 
metacarpal  bone  ;  each,  joining  with  the  tendons  of 
common  extensor,  is  inserted  into  the  base  of  the 
first  phalanx  of  the  corresponding  finger.  iV".  ulnar. 

Interossei  dorsales,  four  in  number,  are  abductors 
from  the  middle  line  of  the  middle  finger.  0.  op- 
posed sides  of  two  metacarpal  bones.  N.  base  of 
first  phalanx  of  each  finger  and  posterior  tendi- 
nous expansion. 

1st,  has  been  already  described  under  the  name 
of  abductor  indicis. 

2nd,  arises  from  second  and  third  metacarpal 
bones,  inserted  into  radial  side  of  base  of  first  pha- 
lanx of  middle  finger. 

3rd,  arises  from  third  and  fourth  metacarpal 
bones  inserted  into  ulnar  side  of  base  of  first  pha- 
lanx of  middle  finger. 

4th,  arises  from  fourth  and  fifth  metacarpal 
bones,  inserted  into  ulnar  side  of  base  of  first  pha- 
lanx of  ring  finger.     N.  ulnar. 


134 

ABDOMEN. 

Ohliquus  externus  vel  descendens. — 0.  external 
surfaces  of  eight  inferior  ribs  at  a  little  distance^ 
from  their  cartilages.  /.  the  fibres  end  in  a  broad 
aponeurosis,  inserted  into  ensiform  cartilage,  linea 
alba,  OS  pubis,  Poupart's  ligament,  anterior  supe- 
rior spinous  process  of  ilium,  and  outer  edge  of  an- 
terior half  of  crista  ilii ;  a  triangular  opening 
formed  by  the  separation  of  the  aponeurotic  fibres, 
the  inner  passing  to  the  symphysis  pubes,  the  outer 
to  the  spine  of  pubes,  is  called  the  external  ab- 
dominal  ring.     N.  intercostals  and  first  lumbar. 

Ohliquus  internus  vel  ascendens. — 0.  fascia  lum- 
borum,  anterior  two-thirds  of  crista  ilii,  and  ex- 
ternal half  of  Poupart's  ligament.  I.  cartilages 
of  seven  inferior  ribs,  ensiform  cartilage,  linea 
alba,  also  by  conjoined  tendon  into  symphysis  and 
upper  edge  of  pubes,  and  into  linea  ilio-pectinea. 
A^.  intercostals  and  first  lumbar. 

Cremaster. — This  muscle,  formed  by  the  lower 
fibres  of  internal  oblique,  is  here  described,  though 
a  muscle  of  the  testicle.  0.  inner  surface  of  ex- 
ternal third  of  Poupart's  ligament,  and  from  lower 
edge  of  ohliquus  internus,  and  sometimes  from 
transversalis  ;  the  fibres  pass  through  the  external 
abdominal  ring,  forming  loops,  both  in  front  and 
behind  the  spermatic  cord.  I.  crest  of  the  pubes. 
N.  genito-crural. 


Transversalis. — 0.  fascia  lumborum,  anterior 
three-fourths  of  crista  ilii,  iliac  third  of  Poupart's 
ligament,  and  inner  side  of  six  inferior  ribs.  /. 
along  with  posterior  lamina  of  obliquus  internus, 
into  the  whole  length  of  linca  alba,  and  upper  edge 
of  pubes.      N.  lower  intercostals  and  first  lumbar. 

Rectus. — 0.  upper  and  anterior  part  of  pubes. 
/.  ensiform  cartilage,  and  cartilages  of  fifth,  sixth, 
and  seventh  ribs.  N.  lower  intercostals  and  iirst 
lumbar. 

Pyramklalis, — 0.  broad  from  pubes.  /.  linea 
alba  midway  to  umbilicus ;  sometimes  wanting. 

DEEP   MUSCLES    OF    THE    ABDOMEN. 

Diaphragm,  is  a  thin  muscular  and  aponeurotic 
septum  between  the  chest  and  abdomen.  0.  two 
crura,  posterior  surfaceof  ensiform  cartilage,  inter- 
nal surfaces  of  cartilages  of  the  six  lower  ribs,  ex- 
ternal ligamentum  arcuatum,  and  convex  edge  of 
internal  ligamentum  arcuatum.  /.  central  ten- 
don. There  are  three  openings  in  diaphragm  :  1, 
for  aorta ;  2,  for  cesophagus  ;  3,  for  vena  cava  infe- 
rior.   N.  phrenic. 

Crura  of  diaphragm. — 0.  light  crus,  from  fore 
part  of  bodies  of  four  superior  lumbar  vertebrae. 
Left  crus  from  the  sides  of  the  two  or  three  supe- 
nor  lumbar  vertebrae.  /.  posterior  border  of.  cor- 
diform  tendon. 


136 

Quadratus  Jumhorxim. — 0.  posterior  fifth  of  spine 
of  iiium,  and  from  ilio-lunibar  ligament.  1.  ex- 
tremity of  transverse  processes  of  four  superior 
lumbar  vertebrae,  also  inner  surface  of  posterior 
half  of  last  rib.     iV.  intercostals. 

Psoas  parvus. — 0.  side  of  last  dorsal  and  first 
lumbar  vertebrae.  /.  linea  ilio-pectinea,  fascia 
iliaca,  and  fascia  lata,  behind  the  femoral  vessels; 
sometimes  wanting. 

psoas  marjnus. — 0.  sides  of  bodies  of  last  dorsal, 
and  from  bodies  and  transverse  processes  of  all  the 
lumbar  vertebrae;  also  from  inter- vertebral  liga- 
ments. /.  inferior  part  of  lesser  trochanter  and 
ridge  below  that  process.     N.  lumbar  nerves. 

lUacus. — 0.  iliac  fossa,  with  inner  margin  of  the 
crista;  two  anterior  spines  of  ilium,  and  interv^en- 
ing  notch,  base  of  the  sacrum,  ilio-lumbar  liga- 
ment, and  capsule  of  hip-joint.  /.  common  tendon 
with  psoas  magnus  ;  the  inferior  fibres  are  inserted 
into  anterior  and  inner  surface  of  femur,  below  tro- 
chanter minor.    N.  anterior  crural. 


MUSCLES    OF    3IALE    PERINEUM. 

Sphincter  ant. — 0.  ano-coccygeal  ligament.  L 
into  raphe',  superficial  fascia,  and  common  central 
point  of  perinaeum.     N.  pudic. 

Sphincter  internus,  encircles  the  lower  part  of 
rectum.     N.  pudic. 


137 

Erector  pern's. — 0.  inner  surface  of  tuber  ischii, 
and  from  insertion  of  great  sciatic  ligament.  /. 
fibrous  membrane  of  crus  penis.    N.  pudic. 

Accelerator  urince. — 0.  central  tendon  and  raphe 
of  perinajum.  I.  anterior  tibres  around  body  of 
penis ;  middle  fibres  surround  the  bulb  and  lower 
fibres  into  triangular  ligament.     N.  pudic. 

Transversalls  perincei. — 0.  inside  of  tuber  ischii. 
I.  central  tendon  of  perinoeum.     N.  pudic. 

Levator  ani. — 0.  posterior  part  of  boily  of  pubes, 
spine  of  the  ischium,  and  between  these  points  the 
angle  of  division  of  deep  pelvic  fascia  into  obturator 
and  vesical.  /.  anterior  fibres  into  central  point 
of  perinseum  and  prostate ;  middle  fibres  into  side 
of  rectum,  posterior  fibres  into  back  part  of  rectum, 
and  OS  coccygis.    N.  sacral. 

Compressor  urethrce. — 0.  This  muscle  is  more  cor- 
rectly described  as  arising  by  a  narrow  tendon  from 
the  ramus  of  the  pubes  on  either  side,  and  as  ter- 
minating in  fleshy  fibres,  which  decussate  in  the 
mesial  line,  some  passing  above,  others  passing  be- 
low, the  membranous  portion  of  the  urethra.  N.  pu- 
dic. 

Coccjjfjeus. — 0.  inner  surface  of  spine  of  ischium. 
/.  extremity  of  sacrum  and  side  of  coccyx.  N, 
sacral. 

MUSCLES    OF    FEMALE    PERINEUM. 

Sphincter  am,  as  in  the  male. 


138 

Levator  ani. — 0.  as  in  the  male.  /.  it  forms  a 
loop  round  the  vagina,  as  well  as  around  the  urethra 
and  rectum. 

Cocci/geus,  as  in  the  male. 

Transversalis  perinceif  as  in  the  male. 

Erector  clitorid'is.  —  0.  inner  surface  of  tuber 
ischii,  and  insertion  of  great  sciatic  ligament.  /. 
fibrous  membrane  of  crus  clitoridis. 

Sphincter  vagince,  represents  the  accelerator 
urinae  in  the  male,  and  extends  from  the  clitoris 
superiorly,  around  each  side  of  vagina,  to  central 
point  of  perinaeum,  in  front  of  anus. 

MUSCLES    OF    THE    INFERIOR    EXTREMITY. 

Fore  Part  and  Sides  of  the  Thigh. 

Tensor  fascia  femor in. — 0.  external  part  of  an- 
terior superior  spine  of  ilium.  /.  fascia  lata, 
about  three  inches  below  the  great  trochanter.  N. 
gluteal. 

.  Sartorius. — 0.  anterior  superior  spine  of  ilium 
and  notch  beneath  it.  /.  inner  side  of  upper  end 
of  tibia,  below  its  tubercle.  N.  middle  cutaneous 
of  anterior  crural. 

Rectus  femoris. — 0.  by  two  strong  tendinous 
heads :  the  outer  from  rough  surface  above  the 
acetabulum  ;  the  inner  from  anterior  inferior  spine 
of  ilium.  I.  upper  edge  of  patella.  N.  anterior 
crural. 


139 

Vastus  externus. — 0.  base  and  anterior  part  of 
great  trochanter,  outer  edge  of  linea  aspera,  oblique 
ridge  leading  to  external  condyle,  external  surface 
of  femur,  and  fascia  lata.  /.  external  edge  of 
tendon  of  rectus,  side  of  patella,  and  head  of  tibia. 
N.  anterior  crural. 

Vastus  internus. — 0.  base  of  small  trochanter 
and  line  leading  from  it  to  linea  aspera,  anterior 
partof  femur,  inner  edge  of  linea  aspera,  and  ridge 
leading  to  inner  condyle.  /.  inner  edge  of  tendon 
of  rectus,  patella,  and  head  of  tibia.  N.  anterior 
crural. 

Crureus. — 0.  anterior  and  external  part  of  femur, 
commencing  at  linea  inter-trochanterica,  and  ex- 
tending along  three-fourths  of  the  bone,  as  far  out- 
wards as  linea  aspera.  /.  upper  and  outer  edge 
of  patella.    N.  anterior  crural. 

The  rectus,  crureus,  and  two  vasti  arc  sometimes 
described  as  one  muscle,  named  quadriceps  exten- 
sor cruris. 

Suh-crureus  or  capsularis. — 0.  inferior  fourth  of 
anterior  surface  of  femur.  I.  synovial  membrane 
of  knee  joint.     N.  anterior  crural. 

Gracilis. — 0.  lower  part  of  body  and  ramus  of 
pubes,  and  part  of  ascending  ramus  of  ischium, 
from  a  surface  two  inches  and  a  half  in  length.  /. 
superior  part  of  internal  surface  of  tibia.  N, 
obturator. 

Pectineus. — 0.  pectineal  line  external  to  spine  of 


140 

pubes,  and  smooth  surface  of  bone  in  front.  I. 
rough  ridge  leading  from  lesser  trochanter  to  linea 
aspera.    N.  anterior  crural  and  obturator. 

Adductor  Muscles. 

1st,  adductor  longus. — 0.  anterior  surface  of 
pubes,  between  spine  and  symphysis.  /.  middle 
third  of  linea  aspera.     N.  obturator. 

2nd,  adductor  hrevis, — 0.  anterior  inferior  sur- 
face of  pubes,  between  symphysis  and  thyroid  for- 
amen. /.  superior  third  of  internal  root  of  linea 
aspera  to  three  inches  below  lesser  trochanter.  N 
obturator. 

Zrd,  adductor  magnus. — 0.  anterior  surface  of 
descending  ramus  of  pubes,  ramus  of  ischium,  and 
external  border  of  its  tuberosity  /.  rough  ridge 
leading  from  great  trochanter  to  linea  aspera,  li- 
nea aspera,  and  internal  condyle  of  femur.  N. 
obturator  and  great  sciatic. 

MUSCLES    OF    HIP. 

Gfufeus  mnximm. — 0.  posterior  fifth  of  crista 
ilii,  the  rough  surface  between  it,  and  superior 
semicircular  ridge,  posterior  ilio-sacral  ligaments, 
lumbar  fascia,  spines  of  sacrum,  side  of  coccyx, 
and  great  sciatic  ligament.  /.  rough  ridge  leading 
from  great  trochanter  to  linea  aspera,  upper  third 
of  linea  aspera,  and  fascia  lata.  N.  small  sciatic 
and  gluteal. 


141 

On  reflecting  the  gluteus  maximus,  we  bring 
into  view  the  gluteus  medius,  pyriformis,  gluteal 
artery  and  nerve,  ischiatic  artery,  greater  and 
lesser  ischiatic  nerves,  pudic  artery  and  nerve, 
tendon  of  the  obturator  internus,  with  the  gemelli, 
the  quadratus  femoris,  and  coccygeus.  Biceps, 
scmi-tendinosus,  semi-membranosus,  adductor  mag- 
nus,  vastus  externus,  internal  circumflex  artery, 
tuber  ischii,  great  trochanter  and  its  bursa,  greater 
and  lesser  sacro-sciatic  ligaments,  and  first  perfo- 
rating artery. 

Gluteus  medius. — 0,  deep  surface  of  fascia,  an- 
terior three-fourths  of  crista  ilii,  superior  semi- 
circular ridge,  and  surface  of  ilium.  /.  upper  and 
outer  part  of  great  trochanter.  N.  superior 
gluteal. 

Gluteus  minimus. — 0.  inferior  semicircular  ridge 
on  dorsum  of  ilium,  rough  surface  between  it  and 
edge  of  acetabulum.  /.  upper  and  anterior  part 
of  great  trochanter.     N.  superior  gluteal. 

Pyriformis. — 0.  concave  aspect  of  second,  third, 
and  fourth  divisions  of  sacrum,  upper  and  back 
part  of  ilium,  and  anterior  surface  of  great  sciatic 
ligament.  /.  upper  part  of  great  trochanter, 
behind  the  insertion  of  gluteus  minimus.  N.  sa- 
cral plexus. 

Gemellus  superior. — 0.  spine  of  ischium.  /.  top 
of  great  trochanter.    N.  sacral  plexus. 

Gemellus  inferior. —  0.  upper  part  of  tuber  ischii, 


143 

and  great  sciatic  ligament.  /.  top  of  great  tro- 
chanter.    N.  sacral  plexus. 

Obturator  interims. — 0.  pelvic  surface  of  obtu- 
rator membrane,  circumference  of  obturator  fora- 
men, and  obturator  fascia.  /.  top  of  great  tro- 
chanter.    N.  sacral  plexus. 

Quadratus  femoris. — 0.  external  surface  of  tuber 
ischii.  /.  linea  quadrata,  or  line  leading  from 
great  trochanter  to  linea  aspera,  above  the  inser- 
tion of  adductor  magnus.     iV".  sacral  plexus. 

Obturator  exteimus. — 0.  inferior  surface  of  obtu- 
rator membrane  and  surrounding  surfaces  of  pubes 
and  ischium.  /.  trochanteric  fossa.    N.  obturator. 


MUSCLES    ON   BACK    PART  OF    THIGH. 

Biceps. — Long  head:  0.  outer  and  back  part 
of  tuber  ischii,  by  a  tendon  common  to  it  and  to 
the  semi-tendinosus.  Short  head:  0.  linea  aspera, 
from  below  insertion  of  gluteus  maximus  to  within 
two  inches  of  external  condyle.  /.  head  of  fibula. 
iV.  great  sciatic. 

Semi-tendinosus. — 0.  tuberosity  of  ischium,  and 
from  three  inches  of  the  tendon  of  the  long  head 
of  biceps.  /.  inner  surface  of  tibia,  below  tuber- 
osity.    N.  great  sciatic. 

Semi-membranosus. — 0  .upper  and  outer  part  of 
tuber  ischii.  /.  inserted  by  three  portions :  1st, 
into  head  of  tibia,  the  tendon  passing  under  inter- 


143 

nal  lateral  ligament ;  2nd,  into  the  fascia  covcriKg 
the  popliteus  muscle ;  Srd,  into  external  condyle  of 
femur,  crossing  the  knee-joint,  and  forming  the 
ligamentum  posticum  Winslowii.   N.  great  sciatic. 


MUSCLES    ON    ANTERIOR    AND     EXTERNAL     PART 
OF    LEG. 

Tibialis  amicus. — 0.  outer  part  of  superior  two- 
thirds  of  tibia,  inner  half  of  interosseous  ligament, 
fascia  of  leg,  and  intermuscular  septa.  I.  inner 
side  of  internal  cuneiform  bone,  and  base  of  first 
metatarsal  bone.   N.  anterior  tibial. 

Extensor  digitorum  longus. — 0.  external  part  of 
head  of  tibia,  head  and  upper  three-fourths  of 
fibula,  part  of  interosseous  ligament,  fascia  of  leg, 
and  intermuscular  septa.  /.  last  phalanges  of  four 
outer  toes.      N.  anterior  tibial. 

Peroneus  tertius. — 0.  anterior  surface  of  lower 
third  of  fibula.  1.  base  of  fifth  metatarsal  bone. 
N.  anterior  tibial. 

Extensor  proprius  poUicis. — 0.  inner  edge  of 
middle  third  of  fibula,  interosseous  ligament,  and 
lower  part  of  tibia.  /.  base  of  last  phalanx  of 
great  toe.  It  has  a  special  pulley  beneath  annular 
ligament.     N.  anterior  tibial. 

Extensor  hrevis  digitorum. — 0.  upper  and  ante- 
rior part  of  OS  calcis  calcaneo-astragaloid,  and 
annular  ligaments.  I.  intenial  tendon  into  base  of 


144 

first  phalanx  of  great  toe  ;  the  three  others  join  the 
.  fibular  sides  of  corresponding  tendons  of  extensor 
digitorum  longus.     N.  anterior  tibial. 


MUSCLES   ON   OUTER  PART   OF    LEG. 

Peroneus  longus. — 0.  upper  two-thirds  of  outer 
surface  of  fibula,  fascia  of  leg,  and  intermuscular 
septa.  I.  tendon  passes  in  a  groove  in  os  cuboides 
obliquely  across  the  sole  of  the  foot,  to  become 
attached  to  the  tarsal  end  of  metatarsal  bone  of 
great  toe.     N.  musculo-cutaneous. 

Peroneus  hrevis. — 0.  outer  and  back  part  of 
lower  half  of  fibular  and  intermuscular  septa.  /. 
base  of  metatarsal  bone  of  little  toe.  N,  musculo- 
cutaneous. 

MUSCLES   OF  BACK   OF   LEG. 

Superjicial  Layer. 

Gastrocnemius.  —  0.  internal  head,  upper  and 
back  part  of  internal  condyle  of  femur,  and  oblique 
ridge  above  it ;  external  head,  from  above  external 
condyle.  I.  lower  and  back  part  of  os  calcis.  N. 
internal  popliteal. 

Plantaris. — 0,  back  part  of  femur  above  exter- 
nal condyle,  and  posterior  ligament  of  knee.  /.  pos- 
terior part  of  OS  calcis.    N.  internal  popliteal. 

Solcus.  —  0«  external  head,  from  back  part  of 


145 

head  and  superior  third  of  fibuhi :  internal  head^ 
from  middle  third  of  tibia,  below  insertion  of  popli- 
teus,  and  from  a  tendinous  arch  extending  between 
the  bones  over  the  posterior  tibial  vessels  :  unites 
with  gastrocnemius  to  form  tendo-Achillis.  /.  lower 
and  back  part  of  os  calcis.  N.   internal  popliteal. 

Popllteus. — 0.  depression  on  outer  condyle  of  fe- 
mur, /.flat,  triangular  surf  ace  occupying  the  supe- 
rior posterior  fifth  of  tibia.     N.  internal  popliteal. 

Flexor  longus  dlgitorum. — 0.  j)osterior  flat  sur- 
face of  tibia,  from  below  popliteus  to  within  three 
inches  of  ankle,  fascia,  and  intermuscular  septa.  /. 
last  phalanges  offour  outer  toes.  N.  posterior  tibial. 

Tibialis  posticus. — 0.  posterior  internal  part  of 
fibula,  upper  part  of  tibia,  and  nearly  whole  length 
of  interosseous  membrane.  /.  inferior  and  internal 
tuberosity  on  scaphoid,  internal  cuneiform  and 
cuboid  bones,  and  second  and  third  metatarsal 
bones.     N.  posterior  tibial. 

Flexor  longus  pollicis. — 0.  two  inferior  thirds  of 
fibula,  interosseous  membrane,  and  intermuscular 
septa.  7.  last  phalanx  of  great  toe.  iV,  posterior 
tibial. 

MUSCLES   OF   FOOT. 

First  Layer. 

Abductor  pollicis. — 0.  lower  and  inner  part  of 

OS  calcis,  internal  annular  ligament,  plantar  faseia, 

and  intermuscular  septum.    I.   internal  side  of 

L 


146 

base  of  first  phalanx  of  great  toe ;  there  is  a  sesa- 
moid bone  in  the  tendon.     N.  internal  plantar. 

Flexor  hrevis  digitorum  perforatus. — 0.  inferior 
and  internal  part  of  os  calcis,  plantar  fascia,  and 
intermuscular  septa.  /.  second  phalanges  of  four 
outer  toes.    N.  internal  plantar. 

Abductor  minimi  digiti. —  0.  outer  side  of  os  cal- 
cis, ligament  extending  from  os  calcis  to  outer 
side  of  fifth  metatarsal  bone,  plantar  fascia,  and 
external  intermuscular  septum.  /.  outer  side  of 
base  of  first  phalanx  of  little  toe.  N.  external 
plantar. 

Second  Layer, 

Flexor  accessorius. — 0.  by  two  heads,  one  mus- 
cular from  inner  part  of  os  calcis,  the  other  tendi- 
nous from  outer  side  of  os  calcis.  I.  outer  part 
of  tendon  of  flexor  longus  digitorum.  N.  exter- 
nal plantar. 

Lumhricales. — Four  in  number.  0.  tendons  of 
flexor  longus  digitorum.  /.  internal  side  of  first 
phalanges  of  four  lesser  toes.  N.  external  plantar 
to  two  outer,  internal  plantar  to  two  inner.  Be- 
tween the  flexor  brevis  and  flexor  accessorius  lie 
the  external  plantar  vessels  and  nerves. 

Third  Layer. 

Flexor  hrevis  pollicis. — 0.  by  a  pointed  process 
from  inner  borders  of  os  cuboides,  from  external 


147 

cuneiform  bone,  and  from  the  tendon  of  tibialis 
posticus.  7.  by  two  divisions  into  outer  and  inner 
border  of  base  of  first  phalanx  of  great  toe :  the 
tendons  contain  sesamoid  bones.*  N.  internal 
plantar. 

Adductor  poUicis. — 0.  os  cuboides,  base  of 
second,  third,  and  fourth  metatarsal  bones  and 
sheath  of  peroneus  longus.  I.  base  of  first  phalanx 
of  great  toe.    N.  external  plantar. 

Transversalis  pedis.  —  A  narrow  fasciculus 
stretched  beneath  the  digital  extremities  of  the 
metatarsal  bones.     N.  external  plantar. 

Flexor  hrevin  minimi  digiti. — 0.  fifth  metatarsal 
bones,  and  sheath  of  tendon  of  peroneus  longus.  /. 
inner  side  of  base  of  first  phalanx  of  little  toe.  N. 
external  plantar. 

Fourth  Layer. 

Seven  interossei  muscles.  Three  on  sole  of  foot, 
and  four  upon  its  dorsum. 

Inferiores,  vcl  plan  tares. 

1st.  0.  inner  side  of  third  metatarsal  bone.  /. 
base  of  first  phalanx  of  the  same  toe. 

2nd.  0.  inner  side  of  fourth  metatarsal  bone.  /. 
inner  side  of  first  phalanx  of  the  same  toe. 

3rd.  0.  fifth  metatarsal  bone.  /.  inner  side  of 
base  of  first  phalanx  of  little  toe. 

Superiores,  vel  dorsales ;  they  arise  by  two  heads 
l2 


148 

from  the  contiguous  surfaces  of  the  metatarsal 
bones. 

1st.  0.  internal  side  of  second  metatarsal  bone 
and  outer  side' of  first.  /.  inner  side  of  base  of  first 
phalanx  of  second  toe. 

2nd.  0.  opposite  sides  of  second  and  third  meta- 
tarsal bones,  i.  outer  side  of  first  phalanx  of 
second  toe. 

3rd.  0.  opposite  sides  of  third  and  fourth  meta- 
tarsal bones.  /.  outer  side  of  first  phalanx  of 
middle  toe. 

4th.  0.  opposite  sides  of  fourth  and  fifth  meta- 
tarsal bones.  7.  outer  bide  of  first  phalanx  of  fourth 
toe. 

Nerve,  external  plantar, 

THE    MUSCLES  OF   THE    ORBIT. 

1.  Levator  palpehrm  superioris. — 0.  upper  edge 
of  foramen  opticum.  /.  superior  border  of  upper 
tarsal  cartilage.     N.  third. 

2.  OhUquus  superior. — 0.  foramen  opticum.  I. 
sclerotic  coat  between  superior  and  external  rectus. 
N.  fourth. 

3.  OhUquus  inferior. — 0.  orbital  edge  of  supe- 
rior maxillary  bone.  /.  sclerotic  coat  between  it 
and  external  rectus  muscle.    N.  third. 


4.  Rectus  superior.  \  ^.    ... 

5.  Rectus    inferior,  ) 


149 

6.  Rectus  internus.    N.  third. 

7.  Rectus  externus.     N.  sixth. 

[All  rise  round  optic  foramen,  the  external  rec- 
tus being  also  attached  to  margin  of  sphenoidal  fis- 
sure, near  the  origin  of  the  superior  rectus,  and 
they  arc  inserted  into  the  sclerotic  coat  about  a 
quarter  of  an  inch  behind  cornea.] 

The  third,  nasal  division  of  fifth,  sixth  nerves, 
and  the  ophthalmic  vein,  pass  between  the  two 
heads  of  the  rectus  externus. 

MUSCLES    OF    INTERNAL   EAR. 

Stapedius. — 0.  within  pyramid.  /.  neck  of 
stapes.     N.  facial. 

Tensor  tympani. — 0.  canal  in  petrous  portion  of 
temporal  bone,  above  Eustachian  tube.  /.  sliort 
process  below  neck  of  malleus.  N.  Meckel's 
ganglion. 

Laxator  tijmpani. — 0.  spinous  process  of  sphe- 
noid bone  and  Eustachian  tube.  /.  processus 
gracilis  of  malleus.   N.  tympanic  branch  of  facial. 

Muscles  occasionally  absent: — Zygomaticus  mi- 
nor, palmaris  longus,  palmaris  brevis,  pyramidalis, 
gemellus  superior,  plantaris,  flexor  brevis  minimi 
digiti,  psoas  parvus,  and  peroneus  tertius. 


150 


THE  BRAIN  AND  ITS  MEMBRANES. 

The  brain  is  surrounded  by  three  membranes — 
the  dura  mater,  arachnoid,  and  pia  mater. 

DURA   MATER. 

A  firm  dense  fibrous  membrane,  adhering  by  its 
outer  surface  to  the  bones  of  the  cranium,  its  in- 
ner surface  being  intimately  connected  with  the 
arachnoid  membrane.  It  supports  the  brain,  acts 
as  an  internal  periosteum  to  the  bones  of  the  skull, 
forms  the  sinuses,  and  sends  sheaths  to  the  several 
nerves  as  they  pass  through  the  cranial  holes.  It 
sends  off  the  following  processes  : 

Falx  cerebri,  commences  narrow  at  crista  galli, 
and  arches  backwards  between  the  lobes  of  the 
cerebrum,  becoming  deeper  until  it  meets  the  ten- 
torium, with  which  process  it  is  continuous  on  each 
side.  Its  convex  edge  corresponds  to  the  median 
groove  of  the  os  frontis,  the  sagittal  edges  of  the 
parietal  bones,  and  the  upper  half  of  the  perpendi- 
cular ridge  of  the  occipital  bone.  The  superior 
longitudinal  sinus  is  in  its  upper  (tdgt,  and  the 
inferior  longitudinal  sinus  in  its  inferior  free  con- 
cave edge. 

Tentorium  cerehelU,  extends  in  a  horizontal  and 
arched  manner  above  the  cerebellum  and  below 
the  posterior  part  of  the  cerebrum.     Its  attached 


151 

borders  contain  the  lateral  sinuses,  and  are  attached 
to  the  transverse  ridges  of  the  occipital  bone,  the 
inferior  posterior  angles  of  the  parietal  bones,  the 
superior  borders  of  the  petrous  portion  of  the  tem- 
poral bones,  and  to  the  clinoid  processes  of  the 
sphenoid  bone. 

Falx  cerebelli,  is  attached  to  the  lower  half  of 
the  perpendicular  ridge  of  the  occipital  bone,  and 
extends  between  the  lobes  of  the  cerebellum  towards 
the  foramen  magnum. 

The  dura  mater  is  supplied  with  nerves  from  the 
fourth,  fifth,  and  eighth  cranial  nerves,  and  sympa- 
thetic. 


Superior  longitudinal  sinus,  of  triangular  form, 
extends  along  the  convex  margin  of  the  falx  cerebri. 
It  commences  by  a  small  vein  in  the  foramen 
caecum,  and  increasing  in  size  as  it  proceeds  back- 
wards, pours  its  blood  into  the  torcular  Hcrophili. 
Its  interior  is  crossed  by  small  bands  called  chordce 
Wdlisii,  and  presents  the  openings  of  the  veins 
which  course  upon  the  upper  surface  of  the  cerebral 
hemispheres,  and  a  number  of  small  whitish  masses 
called  glandulce  Pacchioni.  Upon  the  outer  surface 
of  the  outer  wall  of  the  sinus,  between  it  and  the 
cranium,  are  situated  the  glandulce  Pacchioni  ex- 
terncB. 

Inferior  longitudinal  sinus    is   very   small,  runs 


along  the  concave  edge  of  the  falx  cerebri,  and  ter- 
minates in  the  straight  sinus. 

Straight  sinus,  passes  from  the  termination  of  the 
inferior  longitudinal  sinus  downwards  and  back- 
wards, receiving  the  blood  of  the  venjE  Galeni, 
and  empties  itself  into  the  torcular  Herophili. 

Lateral  sinuses,  each  corresponds  to  the  trans- 
verse groove  in  the  occipital  bone,  the  groove  in  the 
posterior  inferior  angle  of  the  parietal  bone,  the 
mastoid  fossa  of  the  temporal  bone,  and  the  groove 
in  the  occipital  bone  on  each  side  of  the  foramen 
magnum  ;  it  passes  through  the  foramen  lacerum 
postcrius  and  becomes  the  jugular  vein. 

Torcular  Herophili,  corresponds  to  the  centre  of 
the  internal  occipital  protuberance ;  six  sinuses  com- 
municate with  it — ^viz.,  the  two  lateral,  the  superior 
longitudinal,  the  straight,  and  the  two  occipital. 

Cavernous  sinuses,  each  extends  from  the  anterior 
clinoid  process  to  the  petrous  portion  of  the  tem- 
poral bone ;  and,  upon  being  cut  into,  presents  a  cel- 
lular appearance.  The  internal  carotid  artery,  the 
sixth  nerve,  and  branches  of  the  sympathetic  nerve, 
are  found  within  each,  but  separated  from  the  blood 
by  the  reflected  venous  lining  membrane.  In  the 
outer  wall  of  each  run  the  third  and  fourth  nerves, 
and  the  first  branch  of  the  fifth  ;  the  sinus  of  each 
side  presents  the  openings  of  the  ophthalmic  vein, 
of  the  two  petrosal  sinuses,  and  of  the  circular 
sinus. 


153 

Circular  sinus,  surrounds  the  pituitary  body,  and 
is  formed  of  an  anterior  and  posterior  transverse 
vein,  which  extends  from  one  cavernous  sinus  to 
the  other. 

Superior  petrosal  sinuseSy  each  passes  from  the 
cavernous  sinus  along  the  upper  border  of  the 
petrous  portion  of  the  temporal  bone,  to  the  lateral 
sinus. 

Inferior  petrosal  sinuses,  each  passes  from  the 
cavernous  sinus  downwards  and  backwards,  along 
the  line  of  contact  of  the  petrous  portion  of  the 
temporal  bone,  and  the  occipital  to  the  lateral 
sinus,  where  this  terminates  in  the  internal  jugular 
vein. 

Transverse  sinus,  crosses  the  basilar  process  of 
the  occipital  bone,  and  connects  the  inferior  petro- 
sal sinuses. 

Occipital  sinuses,  tw^o  in  number,  are  contained 
in  the  falx  cercbelli,  and  open  into  the  torcular 
Herophili.  Not  infrequently  these  two  join  to 
form  a  single  sinus  before  opening  into  the  space. 

TUNICA    ARACHNOIDEA, 

Belongs  to  the  class  of  serous  membranes,  is 
spread  over  the  surface  of  the  brain  without  dip- 
ping down  into  its  sulci,  and  is  reflected  upon  the 
dura  mater,  in  those  situations  where  the  nerves 
and  veins  pierce  this   fibrous  membrane  :  thus, 


154 

after  the  manner  of  all  serous  membranes,  it  forms 
a  shut  sac,  and  consists  of  a  parietal  and  a  visceral 
layer.  Its  parietal  layer  is  in  contact  with  the 
dura  mater  except  at  certain  places  where  it  forms 
the  subdural  cavity  ;  while  the  visceral  layer  is  sep- 
arated from  the  subjacent  pia  mater  in  many  posi- 
tions, forming  the  subarachnoid  space, which  is  more 
apparent  in  some  places  than  in  others.  Among 
the  most  marked  is  one  at  the  base  of  the  brain, 
at  the  inter-peduncular  space  and  the  fourth  ven- 
tricle ;  it  is  at  the  latter  place  that  the  subarach- 
noid space  communicates  with  the  ventricles  of 
the  brain  through  the  foramen  of  Majendie.  In 
the  subarachnoid  space  is  contained  the  cerebro- 
spinal fluid  ;  and  some  fluid  also  exists  in  the  sub- 
dural space.  This  fluid  contains  98.5  per  cent,  of 
water  and  1.5  of  animal  and  saline  matters. 

Glandidce  Pacchioni,  arc  flattened,  pulpy-looking 
bodies  which  extrude  through  the  dura  mater,  and 
are  also  found  in  the  longitudinal  sinus,  and  in 
other  situations.  They  are  hypertrophies  of  the 
normal  villi  of  the  arachnoid. 


PIA   MATER. 

The  vascular  covering  of  the  brain  lines  its  entire 
surface,  dipping  between  its  convolutions  and  send- 
ing numerous  blood-vessels  into  its  substance ;  it  is 
intimately  connected  to  the  arachnoid  membrane 


by  its  outer  surface,  except  at  the  base  and  sulci  of 
brain ;  and  entering  the  ventricles  by  the  great 
transverse  fissure,  forms  the  velum  interpositum 
and  choroid  plexuses.  It  obtains  a  large  nerve 
supply  from  the  third,  sixth,  facial,  pneumogastric 
spinal  accessory  and  sympathetic  nerves. 


THE  BRAIN. 

The  brain  is  subdivided  in  to  four  portions — viz., 
the  cerebrum,  the  cerebellum,  the  medulla  oblongata, 
and  the  pons  Varolii. 

Weight  about  49  oz.  in  the  male,  and  44  oz.  in 
the  female. 

THE  CEREBRUM. 

This,  the  largest  of  the  four  divisions,  is  of  oval 
form,  and  is  divided  into  two  equal  portions,  called 
hemispheres,  by  a  fissure  (longitudinal)  which  ex- 
tends along  the  medial  line  upon  its  upper  surface, 
and  contains  the  falx  cerebri  and  the  anterior 
cerebral  arteries.  At  the  base  of  the  brain  the 
hemispheres  are  divided  at  each  extremity  by  this 
fissure,  but  in  the  centre  they  are  united. 

Hemispheres,  right  and  left,  are  convex  superiorly 
and  externally,  and  flat  towards  each  other,  where 
they  correspond  to  the  falx ;  on  the   under  surface 


156 

tliey  rest  on  the  anterior  and  middle  fossa,  and  the 
tentorium  cerebelli. 

Convolutions,  or  gyri,  are  eminences,  longitudinal 
and  rounded,  and  directed  in  various  ways  uj^on  the 
surface  of  each  hemisphere. 

Sulci,  are  the  depressions  which  separate  the 
convolutions  from  each  other,  over  which  the  arach- 
noid membrane  passes,  but  into  which  the  pia  ma- 
ter dips. 

Grey  matter  of  brain,  is  of  brownish-grey  col- 
our, from  three  to  four  lines  in  thickness,  soft 
and  vascular,  and  for  the  most  part  situated  upon 
the  outer  surface  of  the  brain.  It  is  however 
found  in  striae,  and  masses  in  the  interior  of  the 
brain.  In  some  situations  its  colour  assumes  a  dark 
hue,  as  is  seen  in  a  section  of  the  crus  cerebri. 
Microscopic  examination  shows  that  it  is  composed 
of  cells  containing  nuclei  and  granules ;  hence  it  is 
sometimes  called  "  vesicular  matter." 

Medullary  substance,  white  and  fibrous,  forms  the 
greater  part  of  the  brain. 

Lobes,  are  five  in  number:  frontal,  parietal, 
occipital,  temporo-sphenoidal,  and  central  or  island 
of  Red.  The  first  three  correspond  fairly  with  the 
bones  beneath  which  they  are  placed ;  the  temporo- 
sphenoidal  occupies  the  middle  fossa,  the  central  is 
found  in  the  fissure  of  Sylvius. 

Primary  fissures :  fissure  of  Sylvius  begins  at 
the  base  of  the  brain,  and  corresponds  to  the  lesser 


157 

wing  of  the  sphenoid  bone.  It  shortly  divides  into 
two  rami,  an  ascending,  about  an  inch  in  length, 
and  a  posterior,  which  runs  horizontally  back- 
wards, separating  the  parietal  from  the  temporo- 
sphenoidal  lobes.  In  angle  formed  by  the  two 
divisions  of  the  fissure  is  the  island  of  Reil. 

Fissure  of  Rolando  passes  upwards  and  back- 
wards, commencing  just  above  the  fissure  of  Syl- 
vius, and  ends  near  the  longitudinal  fissure.  It 
separates  the  frontal  from  the  parietal  lobes. 

Parleto-occipital  fissure,  seen  on  the  median 
aspect  of  the  hemisphere,  passes  downwards  and 
forw^ards  towards  the  corpus  callosum.  It  passes 
outwards  on  the  external  surface  of  the  brain  for 
about  an  inch,  and  separates  the  parietal  and  occi- 
pital lobes. 

Lobes— frontal  lobe  has  four  convolutions  on  its 
outer  surface,  superior,  middle,  and  inferior  frontal, 
separated  by  the  superior  and  inferior  antero-pos- 
terior  fissures ;  and  the  ascending  frontal  convo- 
lution, which  is  placed  in  front  of  the  fissure  of 
Rolando.  Its  orbital  surface  presents  the  olfactory 
and  orbital  sulci,  with  the  straight  convolution 
between  them. 

Parietal  lobe  presents  five  convolutions,  the 
ascending  parietal,  placed  behind  the  fissure  of 
Rolando,  the  superior  and  inferior  parietal  lobules, 
separated  by  the  interparietal  fissures ;  the  supra 
marginal  and  the  angular  gijri. 


158 

Occipital  lobe  has  three  convohitlons,  superior, 
middle,  and  inferior  occipital,  separated  by  the 
superior  and  inferior  occipital  fissures  :  these  gyri 
are  connected  with  the  parietal  and  temporo-sphe- 
noidal  lobes  by  three  or  four  annectant  gyri. 

Temporo-sphenoidal  lobe  :  composed  of  three  gyri, 
superior,  middle,  and  inferior,  divided  by  the  parallel 
and  the  inferior  temporo-sphenoidal  fissures. 

Central  lobe,  or  island  of  Reil,  consists  of  six 
gyri,  and  corresponds  -with  the  extra-ventricular 
portion  of  the  corpus  striatum.  Is  found  in  the 
fissure  of  Sylvius. 

The  inner  or  median  surface  of  the  hemisphere 
presents  the  following  fissures  : — 

Parieto-occipital,  already  described. 

Calcarine  commences  at  the  back  part  of  the 
hemisphere,  runs  forwards,  and  joins  at  an  acute 
angle  the  parieto-occipital  fissure. 

Calloso-marginal  commences  below  the  corpus 
callosum,  courses  round  its  genu,  along  its  upper 
surface,  whence  it  inclines  upwards  to  end  behind 
the  fissure  of  Rolando :  between  it  and  the  corpus 
callosum  is  the  gyrus  of  the  latter. 

Convolutions  Marginal,  runs  along  the  longitu- 
dinal fissure. 

Gyrus  fornicaius,  or  convolution  of  the  corpus  cal- 
losum, skirts  the  corpus  callosum. 

Quadrate,  or  prcecuneus,  between  the  calloso- 
marginal  and  parieto-occipital  fissures. 


159 

Cuneus,  wedge-shaped,  between  the  parleto* 
occipital  and  calcarine  fissures. 

The  under  surface  of  the  temporo-sphenoidal 
and  occipital  lobes  are  continuous  and  present  three 
gyri,  superior  occiplto-temporal  or  uncinate,  infe- 
rior and  middle  occipito-tempwal :  and  two  fis- 
sures, the  dentate  or  hippocampal,  and  the  col- 
lateral. 

Locus  perforatus  anticus,  is  perforated  by  a  num. 
ber  of  small  foramina,  for  branches  of  the  anterior 
choroid  arteries ;  it  is  situated  external  to  the 
optic  commissure. 

Optic  commissure^  the  junction  of  the  two  optic 
tracts  in  the  middle  line. 

Tuber  cinereum,  a  mass  of  grey  matter  behind 
the  optic  commissure,  to  which  is  attached  the  m- 
fundihulum,  a  hollow,  funnel-shaped  process  of 
grey  matter,  which  ends  in  the  pituitary  body. 

Corpora  aUncaniia,  two  rounded  masses^  which 
con-espond  to  the  turn  of  the  anterior  crura  of  the 
fornix. 

Locus  j)erforatus  posticus^  is  perforated  by  small 
apertures,  for  the  passage  of  arteries  to  the  optic 
thai  ami. 

Centrum  ovale  minus,  is  the  section  made  of  the 
cerebrum  within  a  few  lines  of  the  corpus  gallo- 
sum  ;  an  oval  surface  of  white  matter  is  seen  sur- 
rounded by  the  grey  cortical  substance. 

Centrum  ovale  majus,  a  term  applied  to  the  sec- 


IGO 

tion  wlilcli  is  made  by  slicing  the  cerebrum  to  a 
level  with  the  corpus  callosum. 

Corpus  callosum,  is  the  white  commissure  con- 
necting the  two  hemisj^heres ;  it  is  about  four 
inches  in  length,  and  presents  upon  its  upper  sur- 
face a  median  groove— ^Ae  raphe — which  corre- 
sponds to  the  anterior  cerebral  arteries,  and  from 
which,  on  each  side,  pass  the  connecting  transverse 
fibres  of  the  hemispheres,  called  lincae  transversoe. 
It  unites  by  its  posterior  extremity  with  the  fornix 
and  the  hippocampus,  mnjor  and  minor;  its  ante- 
rior extremily  being  curved  upon  itself,  the  genu 
turns  back ;  the  reflected  portion,  the  rostrum,  gra- 
dually tapers  off  on  each  side  to  form  the  peduncles 
of  the  corpus  callosum,  while  the  central  portion, 
the  lamina  cinerea,  is  connected  with  the  optic  com- 
missure, and  tuber  cinereum  at  the  base  of  the 
brain. 

Lateral  ventricles,  each  consist  of  a  body  and 
three  cornua,  the  body  corresponding  to  the  centre 
of  each  cerebral  hemisphere,  the  cornua  proceeding 
one  to  each  lobe.  The  bodies  of  the  ventricles  are 
separated  from  each  other  by  the  septum  lucidum. 

Anterior  horn,  passes  forwards  and  outwards  in 
the  anterior  lobe :  in  it  is  seen    the  corpus   stri- 

Middle  horn,  passes  backwards,#3ut\^rds,  down- 
wards, forwards,  and  inwards  in  the  middle  line :  in 
it  are  seen  the  hippocampus  major,  pes  accessorius, 


IGl 

corpus  fimbriatum,  pes  hippocampi,  choroid  plexus, 
and  optic  thalamus. 

Posterior  horn,  passes  backwards,  outwards,  and 
inwards  in  the  posterior  lobe ;  in  it  are  seen  the 
hippocampus  minor  and  pes  acccssorius. 

Septum  lucidum,  descends  from  the  raph(5  of  the 
corpus  callosum  to  the  fornix,  separating  the  lateral 
ventricles  from  each  other.  It  consists  of  two 
layers,  which  are  composed  of  white  and  of  grey 
matter,  and  lined  by  epithelium ;  the  cavity  be- 
tween them  is  called  the  Jijlh  ventricle  ;  its  form  is 
triangular,  the  apex  corresponding  to  the  union  of 
the  corpus  callosum  and  the  fornix,  the  base  an- 
terior, corresponding  to  the  curved  portion  of  the 
corpus  callosum. 

Fornix,  a  longitudinal  white  commissure,  placed 
horizontally  beneath  the  septum  lucidum  and  cor- 
pus callosum  ;  it  arches  above  the  third  ventricle, 
and  lies  upon  the  velum  intci-positum  and  choroid 
plexus.  Its  body  is  triangular,  and  from  it  pro- 
ceed anteriorly  two  crura,  and  posteriorly  also  two 
crura :  the  anterior  crura  descend  to  the  base  of 
the  brain,  curve  upon  themselves,  forming  the  cor- 
pora albicantia,  then  pass  backwards  and  are  lost 
in  the  optic  thalamus  ;  the  posterior  crura  pass 
backwards  and  outwards,  become  attached  to  the 
hippocampi  majores,  and  are  lost  in  the  descending 
cornu. 

The  hjra  is  the  appearance  presented  upon  the 


163 

under  aspect  of  the  fornix  by  some  transverse  white 
fibres  which  connect  the  hippocampi  and  the  pos- 
terior crura  of  the  fornix. 

Foramen  of  Monro  is  an  opening  on  each  side 
behind  the  anterior  pillars  of  the  fornix,  which  join 
in  the  middle  line  after  passing  downwards  and 
inwards,  and  open  into  the  third  ventricle,  thus 
establishing  a  communication  between  this  and  the 
lateral  ventricles. 

Corpora  striata,  two  pear-shaped  bodies,  their 
bases  being  contained  in  the  anterior  corima  of  the 
lateral  ventricles,  the  narrow  stalk-like  extremities 
being  directed  backwards  into  the  bodies  of  the 
ventricles  :  they  are  grey  on  their  surface,  but  when 
cut  into  present  alternating  striasof  grey  and  white 
matter ;  thus  their  name. 

Optic  tlialami,  two  large  oval  bodies  placed  behind 
and  between  the  coi-pora  striata  ;  each  presents  upon 
its  inferior  surface  two  tubercles,  called  corpora 
geniculata.  Towards  the  median  line  the  optic 
thalami  are  fiat,  and  united  to  each  other  by  a  soft 
structure,  called  soft  commissure  ;  posteriorly  they 
are  also  joined  together  by  the  posterior  commis- 
sure ;  upon  their  external  surface  they  are  white, 
but  their  interior  is  grey. 

Taenia  semicircularis,  a  narrow  white  band, 
situated  in  the  groove  between  the  optic  thalamus 
and  corpus  striatum  of  each  side. 

Choroid  plexus,  the  fold  of  pia  mater  which  lies 


163 

upon  the  optic  thalamus,  end  which  enters  the 
body  of  the  lateral  ventricle  by  the  inferior  cornu ; 
the  choroid  plexus  of  each  side  passes  forwards  and 
inwards,  and  both  unite  in  the  foramen  of  Monro. 

Velum  interpositum,  lying  underneath  the  fornix, 
unites  the  choroid  plexuses  of  either  side  ;  it  is 
composed  of  arachnoid  membrane  and  pia  mater, 
and  contains  in  its  centre  the  vena?  Galeni. 

Venoe.  Galeni,  contained  in  the  velum  interposi- 
tum, pass  from  before  backwards,  and  terminate 
in  the  straight  sinus.  These  veins  return  the 
blood  from  the  choroid  plexuses,  and  from  the 
parts  within  the  ventricles. 

Pineal  hochj,  a  small  conical  reddish-grey  mass, 
containing  in  general  gritty  matter.  It  is  placed 
upon  the  corpora  quadrigemina,  and  is  connected 
with  the  optic  thalami  by  two  peduncles. 

Hippocampus  minor,  an  oval  eminence  in  the  pos- 
terior cornu  of  the  lateral  ventricle ;  white  exter- 
nally, and  grey  in  its  interior.  It  is  the  fold 
which  corresponds  to  the  calcarine  fissure. 

Hippocampus  major,  a  larger  eminence,  and 
placed  in  the  middle  cornu  of  the  lateral  ventricle. 

Pes  hippocampi,  the  tuberculatcd  appearance 
which  the  extremity  of  the  hippocampus  major 
presents. 

Tmnia  hippocampi,  or  corpus  Jimhriatum,  the  free 
margin  of  the  posterior  crus  of  the  fornix,  where 
it  is  connected  with  the  hippocampus  major. 
M  2 


164 

Corpus  dentatum,  a  grey  seiTatecl  line  in  the  in- 
ferior cornu  of  the  lateral  ventricle,  and  which  is 
exposed  upon  removing  the  taenia  hippocampi,  be- 
neath which  it  lies. 

Eminentia  collateralis  or  pes  accessorius  is  a  tri- 
angular smooth  surface  between  the  hippocampus 
major  and  minor.  It  corresponds  to  the  posterior 
ramus  of  the  fissure  of  Sylvius. 

Third  ventricle,  a  deep  fissure  between  the  optic 
thalami,  exposed  by  separating  these  bodies.  It  is 
hounded  anteriorly  by  the  descending  crura  of  the 
fornix,  and  the  anterior  commissure,  posteriorly 
by  the  posterior  commissure  and  the  tubercula 
quadrigemina,  laterally  by  the  optic  thalami  :  its 
floor  corresponds  to  the  lamina  cinerea,  tuber  cin- 
ereum,  infundibulum,  coi'])ora  albicantia,  and  locus 
perforatus  posticus  ;  it  is  covered  in  by  the  velum 
interpositum  and  fornix,  and  is  crossed  by  three 
commissures,  anterior,  middle,  and  posterior. 

Iter  e  leriio  ad  quartum  ventriculum,  an  opening 
in  the  posterior  part  of  the  third  ventricle,  under 
the  posterior  commissure  and  tubercula  quadrige- 
mina, and  leading  obliquely  backwards  and  down- 
wards to  the  fourth  ventricle. 

Anterior  commissure^  a  white,  round  cord,  ante- 
rior to  the  crura  of  the  fornix,  and  passing  trans- 
versely from  one  corpus  striatum  to  the  other. 

Posterior  commissure,  white,  extends  trans- 
versely from  one   optic  thalamus  to  the   other. 


165 

It  is  shorter  and  smaller  than  the  anterior  com- 
missure. 

Middle  commissure,  grey  and  soft,  connects  the 
anterior  parts  of  the  optic  ihalami. 

Corpora  guadrigemina,  four  eminences,  called 
also  nates  and  testes ;  situated  under  the  posterior 
part  of  the  velum  interpositum,  and  the  pineal 
body  ;  the  two  anterior  (the  nates)  are  connected 
to  the  optic  thalami ;  the  posterior  (the  testes)  are 
connected  to  the  cerebellum  by  the  following  pro- 
cesses. 

Superior  peduncles  of  the  cerebellum,  two  white 
plates  which  pass  obliquely  from  the  cerebellum 
upwards  and  inwards  to  the  testes. 

Corpora  geniculata  and  optic  tracts.  The  tracts 
are  flat  bands  which  arise  from  the  under  and  outer 
part  of  the  thalami  and  corpora  quadrigemina  : 
pass  forwards  round  the  c'rus  cerebri  and  decussate 
at  the  optic  commissure.  Two  oval  masses,  corpus 
geniculatum  externum  and  internum,  are  seen  on 
each  side  before  the  optic  tract  bends  forwards. 

Valve  of  Vieussensy  a  layer  of  grey  and  white 
substance,  of  triangular  form,  attached  by  its  sides 
to  the  processus  e  cercbcllo  ad  testes,  by  its  base  to 
the  cerebellum,  and  by  its  apex  to  the  testes. 

Fourth  ventricle,  is  exposed  by  cutting  through 
the  valve  of  Vieussens.  It  is  bounded  anteriorly 
by  the  pons  Varolii,  laterally  by  the  processus  e 
cerebello  ad  testes,  superiorly  by  the  valve  of  Vieus- 


166 

sens,  inferiorly  by  pia  mater  and  arachnoid  rneni- 
brane,  and  posteriorly  by  the  cerebellum. 

On  the  floor  of  the  fourth  ventricle  runs  a  longi- 
tudinal groove  which  ends  below  in  the  calamus 
scriptorius:  on  each  side  is  a  round  eminence, 
fasciculus  teres:  from  the  groove  emerge  several 
white  lines  linece.  transversce  forming  part  of  the 
auditory  nerve.  In  front  and  to  outer  side  of  the 
fasciculus  teres,  is  a  bluish  spot,  locus  cceruleus. 
In  the  posterior  part  of  the  floor  are  nuclei  for  the 
glossopharyngeal,  vagus,  hypoglossal,  and  spinal 
accessory  nerves. 

Choroid  plexus  of  fourth  ventricle,  a  small  fold 
of  pia  mater,  which  enters  the  ventricle  as  this 
membrane  is  passing  from  the  cerebellum  to  the 
spinal  cord. 

CEREBELLUM, 

Consists  of  a  central  portion  called  superior  and 
inferior  vermiform  processes,  and  of  two  hemi- 
spheres, united  inferiorly  by  the  pons  Varolii. 

Hemispheres  are  flat  superiorly,  where  they  cor- 
respond to  the  tentorium,  and  convex  inferiorly 
where  they  lie  in  the  inferior  occipital  fossa :  Ihey 
are  separated  behind  by  a  deep  notch,  and  in- 
feriorly the  two  hemispheres  are  separated  by  a 
deep  fossa,  vallecula.  The  surface  of  each  presents 
semicircular,  parallel,  narrow  lines,  Zaywmoe,  arising 
from  the  disposition  of  the  grey  matter  of  the 


167 

organ  ;  between  these  laminas  the  pia  mater  enters, 
but  the  arachnoid  passes  over  them. 

Great  horizontal  fissure  divides  the  cerebellum 
into  an  upper  and  lower  mass,  running  round  its 
free  border. 

The  upper  surface  of  each  hemisphere  presents 
the  quadrate  and  posterior  superior  lobes :  on  the 
under  surface  are  seen  iha  posterior  inferior,  slender 
hiventral  lobes,  the  amygdala,  and  the  flocculus. 

Superior  vermiflirm  process,  a  small  conical  emi- 
nence corresponding  to  the  superior  and  central 
part  of  the  cerebellum. 

Inferior  vernuform  process,  larger  than  the  supe^ 
rior,  and  corresponding  to  the  inferior  and  central 
part  of  the  cerebellum.  It  presents  the  pyramid, 
uvula,  and  nodule. 

Arbor  vitce,  the  branching  of  the  medullary  sub- 
Stance  of  th3  cerebellum,  exposed  by  making  a 
vertical  section  of  it. 

Corpus  dentatum,  a  small  oval  mass  of  grey 
substance,  surrounded  by  a  yellow  zigzag  line,  and 
exposed  upon  making  a  section  of  the  cerebellum 
parallel  to,  but  an  inch  distant  from,  the  median 
line. 

PONS   VAROLII, 

Is  a  broad  transverse  white  commissure,  con- 
necting the  two  lobes  of  the  cerebellum.  In  the 
median  line  is  a  longitudinal  groove  for  the  basilar 


168 

artery.      Its  appearance  is  striated,  marking  tho 
course  of  its  superficial  fibres. 

MEDULLA   OBLONGATA. 

A  large  pyramidal  process  of  nerve  structure, 
extending  from  the  lower  margin  of  the  pons  Va- 
rolii to  the  commencement  of  the  spinal  cord. 
About  an  inch  and  a  quarter  in  length  it  presents 
an  anterior  and  posterior  median  fissure,  which 
divides  the  medulla  into  two  lateral  portions.  Each 
half  is  composed  of  the  following  columns,  which 
are  separated  from  each  other  by  distinct  grooves. 

Anterior  pyramids. — Two  anterior  white  bundles, 
which  pass  up  beneath  the  pons ;  on  separating 
them,  fibres  are  seen  which  pass  from  one  to  the 
other,  decussation  of  the  pyramids. 

Olivary  bodies. — Two  oval  bodies  placed  exter- 
nal to  the  former ;  contain  in  their  interior  nuclei 
of  grcf  matter,  corpus  dentatum. 

Restiform  bodies^  large,  situated  posteriorly. 

Posterior  pyramids^  small  and  cordlike,  lie  on 
each  side  of  the  posterior  median  fissure. 

BASE    OF   THE   BRAIN, 

Presents  on  each  side  of  the  median  line  the 
anterior  and  middle  lobes  of  the  cerebrum,  separ- 
ated from  each  other  by  the  fissure  of  Sylvius,  and 
a  lobe  of  the  cerebellum  resting  upon  the  posterior 


169 

lobe  of  the  cerebrum.  In  the  median  line,  pro- 
ceeding from  before  backwards,  is  the  anterior 
extremity  of  the  median  fissure  (on  either  side  of 
which  run  the  the  olfactory  nerves),  the  lower  ex- 
tremity of  the  corpus  callosum,  the  optic  commis- 
sure, the  tuber  cinereum,  the  corpora  albicantia, 
the  pituitary  body  and  infundibulum,  the  locus 
perforatus  (on  either  side  of  this  is  the  crus  cere- 
bri), the  pons  Varoh'i,  and  lastly,  the  posterior 
extremity  of  the  median  fissure.  <:Ju/^ 

ORIGIN    OF   THE    CEREBRAL  NERVES.     ^     ^ 

First  nerve  (olfactory)  arises  by  three  roots,  the  . 
external,  long  and  white,  from  the  fissure  of  SyL>^ 
vius,  and  the  island  of  Reil;j(rtie  internal,  also 
white,  from  the  posterior  internaLsurfaee  of  the 
under  part  of  the  anterior  lobe ;  ^SfcTme  middle, 
short  and  grey,  from  a  grey  tubercle  upon  the 
under  surface  of  the  anterior  lobe»t    C\  b  ^ 

Second  (op!ic)  arises  by  two  roots  from  the  cor- 
pora quadrig^niina,  the  corpora  geniculata,  and 
the  optic  thalamus  the  roots  unite  and  form  the 
tractus  opticus,  which  passes  round  and  becomes 
slightly  attached  to  the  crus  cerebri ;  the  tracts,  one 
from  cither  side,  then  unite  in  the  optic  commissure, 
having  previously  received  a  few  fibres  from  the 
tuber  cinereum ;  from  the  anterior  and  outer  part 
of  this  commissure  proceed  the  optic  nerves 
properly  so-called. 


170 

Third  (motor  oculi)  arises  from  the  inner  side  of 
the  crus  cerebri,  near  the  pons  Varolii  ;  its  fibres 
may  be  traced  to  a  grey  nucleus  at  the  floor  of  the 
aqueduct  of  Sylvius.  f  ^j^i^^'  ^^      -ft  ^i^p(    -  - 

Fourth  (trochlearis)  arises  from^he  valve  of 
Vieussens,  by  several  delicate  filaments,  which 
meet  those  of  the  opposite  side  in  the  mesial  line. 

Fifth  nerve  (trigeminal)  consists  of  two  portions, 
a  sensory  and  a  motor.  The  motor  root,  the 
smaller,  a«-ises  from  ihe  pyramidal  tJWSy,  in  the  ^ 

substance  of  the  pons  Varolii,  and  the  outer  angle 
of  the  floor  of  the  fourth  ventricle  :  and  the  sensory 
root,  from  the  fasciculus  teres  and  restiformtftfcct.  •''*'*' "y^ 
Upon  the  sensory  root  is  developed  a  large  gan-  ■••^ ' 
glion,  Gasserian,  the  motor  passing  beneath  it.  ^t/jti 

Sixth  (abducens)  arises  from  the  medulla  passing 
through  the  fibres  of  pyramidal  body  to  a  nucleus 
beneath  the  fasciculus  teres  in  the  floor  of  the 
fourth  ventricle,  and  emerging  from  the  transverse 
groove  of  the  medulla. 

Seventh  nerve  consists  of  the  port lo  dura,  or  facial, 
and   the  portio  mollis,  or    auditory.      The  portio 
dura  arises  from  the  lateral  tract  between  the  oli- 
vary and  rcstiform  bodies,  and  to  the  grey  nucleus  m  j 
before    mentioned.     The  portio    mollis   arises   by     p  *j 
white  striae  from  the  median  fissure  in  the  fouvth  tv^% 
ventricle,  and  is  connected  with  the  calamus  scrip»  (|^^  • 
tori  us  and  the  fl^r^nliiiiii  ,^  <'^^vJ  "^>^ 

Eighth  nerve   consists   of  the  glosso  pharyngeal^ 


171 

pneumogastric,  and  spinal-accessory.  The  glosso- 
pharyngeal  arises  by  four  or  five  filaments  from  a 
grey  nucleus  at  the  floor  of  the  fourth  ventricle, 
between  the  vagal  and  auditory  nuclei,  and  emerges 
from  the  groove  between  the  olivary  and  restiform 
bodies.  The  pneumogastric  arises  by  eight  or  ten 
filaments  from  the  groove  below  the  glosso-pharyn- 
geal ;  its  deep  origin  is  from  the  floor  of  the  fourth 
ventricle.  The  spinal-accessory  arises  by  several 
filaments  from  the  lateral  tract  of  the  medulla  and 
spinal  cord,  and  the  floor  of  the  fourth  ventricle, 
close  to  the  calamus  scriptorius. 

The  ninth  (hypo-glossal),  arises  by  ten  or  fifteen 
filaments  from  the  groove  between  the  pyramidal 
and  olivary  bodies,  about  half  an  inch  below  the 
origin  of  the  sixthr^e  fibres  being  traced  to  the 
floor  of  the  fourth  ventricle,  near  the  middle  line. 

DISTRIBUTION   OF   CEREBRAL  NERVES. 

First  pair  (or  olfactory)  sends  off  three  sets  of 
branches  to  the  upper  part  of  the  nose.  Internal 
branches  to  septum  nasi;  middle  branches  to 
mucous  membrane  of  roof  of  each  nostril ;  and 
external  branches  to  upper  and  middle  spongy 
bones. 

Second  pair  (or  optic)  pierce  the  sclerotic  coat 
of  the  eye,  and  form  the  retina. 

Third  pair  (or  motores  oculorum).      Superior , 


172 

or  smaller  branch,  supplies  the  superior  rectus,  and 
the  levator  palpebrae.  Inferior,  or  larger  branch, 
supplies  the  internal  rectus,  the  inferior  rectus,  and 
the  inferior  oblique ;  and  also  sends  a  branch  to 
the  lenticular  ganglion. 

Fourth  pair  (or  trochleares)  are  distributed  to 
superior  oblique  muscles  of  the  eyes. 

Fifth  pair  (or  trigeminal)  first  from  the  Gasse- 
rian  ganglion,  and  divide  into  three  main  branches 
— viz.,  ophthalmic,  superior  and  inferior  maxillary. 

Ophthalmic  division — Divides  into — 1.  Lachry- 
mal nerve,  which,  passing  along  the  outer  wall  of 
the  orbit,  sends  a  branch  downwards  to  the  orbital 
branch  of  the  superior  maxillary  nerve  ;  then  gives 
filaments  to  the  lachrymal  gland  and  the  conjunc- 
tiva; and  finally,  perforating  the  fibrous  attach- 
ment of  the  upper  eyelid,  terminates  in  the 
integument  of  the  forehead.  2.  Frontal  nei've, 
enters  the  orbit  above  the  levator  palpebrse;  it 
divides  into  supra-orbital  and  supra-trochlear : 
supra-orbital  nerve,  escaping  through  the  supra- 
orbital notch,  is  distributed  to  the  integuments  of 
the  forehead;  the  supra-trochlear  passing  above 
the  pulley  of  the  trochlcaris  muscle,  sends  a  fila- 
ment to  the  infra-trochlear  branch  of  the  nasal 
nerve,  and  terminates  in  the  mucous  membrane  of 
the  inner  canthus  and  in  the  integuments  of  the 
forehead.  3.  Nasal  nerve,  enters  the  orbit  betwe.-n 
the  two  heads  of  the  rectus  extemus  muscle.    It 


173 

gives  a  filament  to  the  lenticular  ganglion,  two  or 
three  ciliary  nerves,  and  the  infra-trochlear  branch  ; 
the  nerve  then  enters  the  skull  by  the  foramen 
ethmoidcum  anterius,  and  escaping  into  the  nose 
by  a  fissure  in  the  cribriform  plate  of  the  ethmoid 
bone,  terminates  at  the  tip  of  the  nose :  the  termi- 
nal filament  is  called  naso-lobular. 

Superior  maxillary  division, — I.  Orbital  branch, 
which  sends  off  a  malar  twig  and  a  temporal  twig. 
2.  Two  brandies  to  Meckel's  ganglion.  3.  Posterior 
dental,  which  sends  off  an  anterior  branch  to  the 
buccinator  muscle  and  gums,  and  a  posterior 
branch  to  the  molar  teeth.  4.  Anterior  dental,  to 
the  antrum  and  front  teeth.  5.  Infra-orbital,  dis- 
tributed to    the  eyelid,  nose,  and  lips. 

Inferior  maxillary  division. — 1.  The  superior  or 
external  branch,  which  is  joined  by  the  motor  por- 
tion of  the  fifth  nerve,  sends  off  deep  temporal 
twigs— a  masseteric  branch  to  masseter  muscle  and 
temporo-maxillary  articulation,  a  buccal  branch  to 
the  buccinator,  and  temporal  muscles,  and  a  ptery- 
goid branch  to  the  pterygoid  muscles.  2.  Infe- 
rior or  internal  branch,  sends  off  the  inferior  dental 
(which  gives  off  the  mylo-hyoid  nerve),  it  supplies 
the  teeth,  and  terminates  in  the  mental  nerve; 
the  gustatory,  which  goes  to  the  glands,  mucous 
membrane,  and  papillae  of  the  tongue,  and  is  joined 
by  the  corda  tympani  nerve ;  and  the  auriculo- 
temporal, which  supplies  the  external  ear,  and  the 


174 

integuments  of  the  side  of  the  head,  and  the  tcm- 
poro-maxillary  articulation. 

The  greater  part  of  the  buccal  nerve  goes  to  the 
mucous  membrane.  The  buccinator  muscle  is 
supplied  by  the  facial  as  its  motor  nerve. 

GANGLIA   IN   CONNEXION   WITH    THE 
FIFTH    PAIR. 

Gasserian  ganglion. — A  large  grey  semilunar 
body,  analogous  to  the  ganglia  upon  the  posterior 
roots  of  the  spinal  nerves.  It  lies  in  a  depression 
at  the  apex  of  the  petrous  portion  of  the  temporal 
bone,  and  presents  anteriorly  a  cmvex  border, 
from  which  proceed  the  three  main  divisions  of 
the  fifth,  just  described.  The  motor  root  of  the  fifth 
nerve  joins  the  inferior  maxillary  division  only. 

The  lenticular  ganglion  is  situated  between  the 
optic  nerve  and  external  rectus  muscle  ;  it  receives 
at  its  pocterior  superior  angle  a  long  filament  from 
the  nasal  branch  of  the  fifth  and  sympathetic 
branches  from  the  cavernous  plexus,  and  at  its 
posterior  inferior  angle  a  branch  from  the  inferior 
division  of  the  third.  Its  anterior  angles  furnish 
the  ciliary  nerves,  about  twenty  in  number,  which 
run  along  the  optic  nerve,  pierce  the  back  part  of 
the  scleroiica,  run  forward  between  it  and  the  cho- 
roid coat,  enter  the  ciliary  ligament,  and  are  ulti- 
mately distributed  to  the  iris. 


175 

MeckeVs  ganrjlion. — A  little  red  body  of  tri- 
angular shape,  situated  deep  in  the  fat  and  cellular 
tissue  of  the  spheno-maxillary  fossa  :  it  communi- 
cates superiorly  by  two  small  twigs  with  the  second 
division  of  the  fifth,  and  sends  off — 1.  Spheno- 
palatine nerve  to  the  mucous  membrane  of  the 
superior  and  middle  spongy  bones  :  it  gives  off  the 
naso-palatine  branch  which  runs  along  the  septum 
nasi,  and  terminates  in  the    foramen    incisivum. 

2.  Palatine  nerve,  which  descends  in  the  palatine 
canal,  and  divides  into  anterior  branches  which 
supply  the  teeth,  and  posterior  and  middle  branches 
which  supply  the  tonsils,  soft  palate,  and  uvula. 

3.  Vidian  nerve,  which  passes  backward  through 
the  Vidian  canal,  enters  the  cranium  b}'  the  foramen 
laccrum  medium,  and  divides  into  an  inferior  and 
a  superior  branch,  having  first  sent  filaments  to  the 
sphenoidal  sinus  :  the  inferior  branch  enters  the 
carotid  canal,  and  unites  with  the  branches  of  the 
sympathetic,  whilst  the  superior  branch  runs  beneath 
the  Gasserlan  ganglion  on  the  petrous  portion  of 
the  temporal  bone,  enters  the  hiatus  Fallopii,  and 
attaches  itself  to  the  portio  dura  nerve.  4.  Pharyn- 
geal, passes  through  the  ptcrygo-palatine  canal  to 
supply  pharynx. 

Otic  ganfjUon,  a  small  body  connected  with  the 
inferior  maxillary  nerve  near  the  foramen  ovale ;  it 
receives  its  motor  root  from  the  branch  to  the  in- 
ternal pterygoid  muscle  ;  its  sensory  from  the  tern- 


176 

poro-auricular,  and  its  sympathetic  from  the  nervi 
molles  around  the  middle  meningeal  artery.  It 
communicates  with  the  lesser  petrosal  nerve  of  the 
glosso-pharyngeal. 

The  naso-palatlne  rjanglion  lies  in  the  anterior 
palatine  foramen,  and  is  formed  by  the  anterior 
palatine  branches  from  Meckel's  ganglion. 

The  suhmaxillay  ganglion  lies  on  the  hyo- 
glossus  muscle,  receives  its  sensory  fibres  from  the 
gustatory  ;  its  motor  from  the  chordaj  tympani, 
and  its  sympathetic  from  the  nervi  molles  around 
the  facial  artery. 

Sixth  pair,  or  ahducenteSy  are  distributed  to  the 
external  rectus  muscle  on  each  side  exclusively, 
and  also  receive  two  filaments  from  the  sympathetic 
in  the  cavernous  sinus. 

Seventh  pair,  consists  of  two  portions — viz., 
portio  dura  and  portio  mollis ;  both  enter  the 
meatus  auditorius  internus. 

Portio  dura,  or  facial  nerve,  passes  through  the 
aqucductus  Fallopii,  and  emerges  at  the  stylo- 
mastoid foramen.  It  gives  off'— 1,  a  branch  to  the 
stapedius  muscle  ;  2,  the  chorda  tympani,  which 
enters  the  tympanum  a  little  below  the  pyramid  ; 
it  then  passes  between  the  handle  of  the  malleus 
and  the  long  process  of  the  incus,  emerges  from 
the  tympanu-H  through  the  canal  of  Iluguier; 
external  to  the  fissuri  Glaseri  unites  with  the 
gustatory  nerve,  and  then  passes  on   to   supply 


177 

the  tongue ;  3,  posterior  auricular  ;  4,  digastric 
5,  stylo-hyoid  neiTcs  :  and  then  divides  into — 1 
cervico-facial  division,  which  gives  off,  buccal 
supra-maxillary  and  infra-maxillary  branches ;  and, 
2,  temporo  facial  division,  which  sends  off  tempo- 
ral, malar,  and  infra-orbital  branches.  The  inter- 
lacement of  the  branches  of  the  facial  nerve,  as  it 
passes  through  the  parotid  gland,  is  called '' pes 
anserinus." 

Portio  mollis,  or  auditor?/  nerve. — 1.  Branch  to 
cochlea.  2.  Branch  to  vestibule  and  semicircular 
canals. 

Portio  intermedia,  a  small  filament  between  the 
portio  dura  and  mollis  ;  and  connects  the  two 
latter  in  the  internal  auditory  meatus. 

Eighth  nerve,  consists  of  three  portions — viz., 
glosso-pharyngeal,  pneumogastric,  and  spinal  ac- 
cessory. They  escape  fromtke  skull  by  the  jugu- 
lar foramen. 

Glosso'pharrjngeal,  or  first  branch  of  the  eighth 
has  two  ganglia,  petrous  and  jugular;  it  gives  off 
— 1,  Jacobson's  neiwe,  which  enters  the  tympanum 
by  a  small  foramen  upon  the  under  surface  of  the 
temporal  bone,  and  sends  a  filament  (small  petro- 
sal to  the  otic  ganglion,  and  carotid  filaments 
which  ramify  on  the  coats  of  the  vessel,  and  com- 
municate with  the  sympathetic  and  vagus  nerves. 
2.  Branches  to  the  pharyngeal  plexus.  3.  Branches 
to  the  tonsillitic  plexus.     4.  Branches  to  the  stylo- 


178 

pharyngeus,  and  superior  and  middle  coDstrictors 
cf  the  pharynx,  mucous  membrane  of  fauces,  &c. 
5.  Branches  to  the  papillae  and  mucous  membrane 
at  the  root  of  the  tongue. 

Pneiunogastric,  or  second  branch  of  the  eighth, 
gives  oft — 1.  Auricular  branches  (ATiiold's)  which 
supply  the  cranial  aspect  of  the  pinna. — 2.  Branches 
to  assist  in  forming  the  pharyngeal  plexus.  3. 
Superior  laryngeal  nerve,  which  gives  off  an  ex- 
ternal laryngeal  branch  to  tlie  exterior  of  the 
larynx,  the  inferior  constrictor  of  the  pharynx, 
and  crico-thyroid  muscle,  and  then  pierces  the 
thyro-h}  oid  membrane  in  company  with  the  supe- 
rior laryngeal  artery,  and  supplies  the  epiglottis, 
mucous  membrane,  and  arytenoid  muscle.  4.  Car- 
diac branches,  to  the  cardiac  nerves  of  the  sympa- 
thetic. 5.  Inferior  laryngeal,  or  recurrent  nerve, 
which  sends  off  cardiac  filaments,  branches  to  the 
fore  part  of  the  trachea  and  thyroid  gland,  and 
branches  to  the  pharynx,  laryngeal  muscles,  and 
mucous  membrane,  on  which  they  commmunicate 
with  branches  of  the  superior  laryngeal.  6.  Pul- 
monary branches,  which  send  off  branches  in  front 
of  the  bronchial  tubes  to  form  the  anterior  or  lesser 
pulmonic  plexus ;  this  plexus  sends  filaments  to 
the  pulmonary  vessels,  also  to  the  lungs  and  peri- 
cardium, and  to  the  posterior  pulmonic  plexus.  7. 
Posterior  or  greater  pulmonic  plexus,  is  formed  by 
the  pneumogastric  nerves,  which  increase  in  size 


179 

at  the  root  of  each  lung,  and  subdivide  and  unite 
in  an  areolar  manner.  This  plexus  is  joined  by- 
several  branches  of  the  sympathetic  nerve,  and 
its  branches  accompany  the  bronchial  tubes 
through  the  substance  of  the  lung.  8.  (Esophageal 
plexus,  or  plexus  gulae;  is  formed  by  the  commu- 
nications of  both  nerves,  encircling  the  oesophagus 
in  their  course  along  this  tube.  9.  Gastric  plexus 
is  formed  by  both  nerves  dividing,  subdividing,  and 
uniting  upon  the  stomach.  The  left  pneumo-gas- 
tric  nerve  is  anterior  upon  the  stomach,  and  sends 
branches  to  the  lesser  omentum  and  liver  ;  the  right 
is  posterior,  and  sends  branches  to  the  splenic  plexus. 

'NfrvusMccessorius,  or  third  branch  of  the  eighth. 
1.  Branches  to  communicate  with  the  eighth, 
ninth  and  sympathetic  nerves.  2.  Branches  to  the 
sterno-clcido-mastoid  muscle,  which  muscle  it  then 
perforates.  3.  Terminal  branches  to  the  trapezius 
muscle.  ^^v  Ub    A  "^  -«.   xT^ 

Ninth  pair,  or  -kr^mtk — i.  Descendens  noni  re- 
ceives a  filament  from  the  pneumogastric,  unites 
with  the  internal  descending  branches  of  the  cer- 
vical plexus,  forming  a  small  plexus,  in  loops,  the 
branches  of  which  pass  to  the  omo-hyoid,  sterno- 
hyoid, and  sterno- thyroid  muscles.  2.  A  branch 
to  the  thyro-hyoid  muscle.  3.  Branches  to  the 
hyo-glossus,  stylo-glossus,  genio-hyoid,  genio-hyo- 
glossus,  hyo-glossus,  and  iingualis  muscles,  and  to 
the  gustatory  branch  of  the  fifth  pair.  4.  Termi- 
N  3 


180 

•  nal  branches  to  the  genio-hyo-glossus  muscle,  and 
muscular  structure  of  the  tongue. 

SPINAL   NERVES. 

Symmetrical^  thirty-one.  pairs — viz.,  eight  cervi- 
cal, twelve  dorsal,  five  lumbar,  five  sacral,  and  one 
coccygeal.  Each  spinal  nerve  has  two  roots,  an 
anterior  and  a  posterior.  The  anterior  is  small, 
and  is  the  motor  division.  The  posterior  large, 
with  a  ganglion  upon  it,  and  is  for  sensation. 
These  roots  are  separated  by  the  cord  itself,  and  by 
the  ligamentum  dentatum.  The  anterior  root  is 
connected  to  the  posterior  root  in  the  inter-verte- 
bral foramen,  beyond  the  ganglion.  On  the  outer 
side  of  the  ganglion  both  nerves  unite  in  a  single 
cord,  which,  after  a  short  course,  divides  into  an 
exterior  and  posterior  branch.  The  posterior 
branches  of  this  division  are  the  smaller  (except  that 
of  the  second  cervical),  and  are  distributed  to  the 
dorsal  muscles  and  integuments.  The  anterior 
branches  fonn  the  several  plexuses  which  supply  the 
muscles  and  mteguments  anterior  to  the  spine,  and 
also  the  extremities. 

DISTRIBUTION    OF    THE    EIGHT    CERVICAL 
NERVES   AND   FIRST   DORSAL   NERVES. 

Posterior  branches,  are  small,  except  the  second 
cervical,  which  perforates  the  complexus  muscle, 


181 

and  accompanies  the  occipital  arteiy ;  the  rest  are 
lost  in  the  neighboring  muscles  and  integuments. 
Anterior  branches. — The  first,  or  sub-occipital, 
twists  round  the  atlas,  to  unite  with  the  second, 
forming  the  nervous  loop  of  the  atlas  :  and  the 
second,  having  received  the  first,  descends  to  unite 
with  the  third.  The  third  unites  in  like  manner 
with  the  fourth,  and  thus  is  formed,  by  the  inferior 
branches  of  the  four  first  cervical  nerves,  the 

CERVICAL  PLEXUS. 

Prom  this  plexus  proceed  : — 
Branches  to  the  platysma,  integuments,  parotid 
gland,  ear,  and  back  of  the  head. 

1.  Great  auricular ^  arises  chiefly  from  the  sec- 
ond and  third  cervical,  and  is  distributed  to  the 
ear,  the  face,  and  the  mastoid  region ;  it  accom- 
panies the  external  jugular  vein. 

2.  Small  occipital,  which,  arising  from  the  second 
cervical,  pierces  the  fascia  behind  the  sterno-mas- 
toid,  and  is  distributed  to  the  integuments  of  the 


3.  Superjicialis  colli,  from  second  and  third  cer- 
vical, is  distributed  to  the  side  and  front  of  the 
neck. 

4.  Descending  branches,  from  third  and  fourth 
cervical,  which  are  divided  into  sternal,  clavicular, 
and  acromial,  and  supply  the  integuments. 


182 

5.  Branches^  generally  two  in  number,  -which 
form  loops  with  the  descendens  noni  in  front  of 
the  internal  jugular  vein. 

6.  Phrenic,  or  internal  respiratory,  which  arises 
from  the  third  and  fourth  cervical,  and  has  a  small 
filament  also  from  the  fifth  cervical :  it  sends 
branches  to  the  liver,  pericardium,  inferior  cava, 
and  terminates  in  the  diaphragm. 

7.  Branches,  which  are  given  to  the  sterno-mas- 
toid  and  trapezius  (these  muscles  are  also  supplied 
by  the  spinal  accessory)  ;  to  the  levator  anguli 
scapula,  the  scaleni,  and  recti  capitis  antici. 

8.  Connecting  branches  with  the  pneumogastric, 
hypoglossal,  and  sympathetic  nerves. 


THE   BRACHIAL   PLEXUS 

Is  formed  by  the  union  of  the  anterior  branches 
of  the  four  inferior  cervical  and  first  dorsal  nerves. 
From  this  plexus  proceed  : — 

1 .  A  branch  to  join  the  phrenic  nerve. 

2.  Branches,  to  the  longus  colli,  scaleni,  and 
sul)-claviu3  muscles. 

3.  The  external  I'espiratori/  nerve  of  Bell,  which, 
arising  from  the  fifth  and  sixth  cervical,  passes 
behind  the  axillary  vessels,  and  is  distributed  to 
the  serratus  magnus. 

4.  Thoracic  nerves,   three  or  four  in  number, 


183 

whicli  forms  loops  around  the  axillary  artery,  and 
supply  the  pectoral  muscles. 

5.  Nerve  to  the  rhomboid  muscles,  arises  from 
the  fifth,  and  passes  through  the  fibres  of  the  sca- 
lenus medius. 

6.  Snpra-scapular  nerve^  which  passes  through 
the  notch  in  the  scapula,  and  supplies  the  supra- 
spinatus  and  infra-spinatus  muscles. 

The  brachial  plexus,  when  in  relation  with  the 
axillary  artery,  resolves  itself  into  three  cords, 
outer,  inner,  and  posterior.  From  the  outer  are 
derived  the  musculo-cutaneous,  the  outer  head  of 
the  median,  and  the  external  anterior  thoracic  ; 
from  the  inner  come  the  internal  anterior  thoracic, 
the  inner  head  of  the  median,  internal  cutaneous, 
lesser  internal  cutaneous  and  ulnar  nerves :  from 
the  posterior  cord  are  derived  the  circumflex, 
musculo-spiral  and  three  subscapular  nervcF. 

7.  Subscapular  nerves,  are  three  or  lour  in  num- 
ber ;  they  descend  behind  the  vessels  to  the  sub- 
scapular, latissimus  dorsi,  and  teres  major  muscles. 

8.  Internal  cutaneous  nerve,  sends  one  branch 
which  descends  over  the  bend  of  the  elbow  as  low 
as  the  wrist,  and  another  branch  which  descends 
towards  inner  condyle,  and  sends  branches  to  inner 
and  posterior  part  of  the  forearm. 

9.  External  cutaneous,  musculo-cutaneous,  or 
perforans  Casserii,  which  sends  branches  to  the 
coraco-brachialis,  biceps,  and  brachialis  anticus ;  an 


184 

anterior  branch  to  the  ball  of  the  thumb  and  palm 
of  the  hand  ;  and  a  posterior  branch  to  the  dorsum 
of  the  hand. 

10.  Median  nerve,  sends  branches  to  the  super- 
ficial and  deep  pronators  and  flexors  of  the  fore- 
arm, except  the  flexor  carpi  ulnaris,  and  half  the 
flexor  digitorum  profundus,which  are  supplied  by 
the  ulnar  nerve  ;  the  anterior  interosseous  nerve, 
which  sends  a  branch  to  the  pronator  quadratus, 
half  the  flexor  profundus  and  flexor  longus  poUicis, 
and  another  to  the  dorsum  of  the  hand  ;  a  super- 
ficial branch  which  is  given  off  above  the  wrist, 
and  which  runs  to  the  palm  of  the  hand ;  and  five 
digital  branches,  which  supply  the  thumb,  index, 
and  middle  fingers,  and  the  radial  side  of  the  ring 
fingers  :  the  muscles  of  the  ball  of  the  thumb,  and 
two  radial  lumbricales. 

11.  Ulnar  nerve,  sends  branches  to  the  skin  of 
forearm,  flexor  profundus,  and  flexor  carpi  ulnaris 
muscles  ;  the  nervus  dorsalis  carpi  ulnaris  to  the 
integuments  on  the  dorsum  of  the  hand  and  the 
two  and  a  half  inner  fingers;  the  superficial 
palmar  branch,  which  divides  into  three  digital 
branches  for  the  supply  of  the  little  finger  and  the 
ulnar  edge  of  the  ring  finger ;  and  the  deep  palmar 
branch  to  join  the  deep  palmar  arch,  which  sup- 
plies  the  inter-ossei  muscles,  two  inner  lumbricales, 
the  adductor  poUicis  muscle,  and  the  deep  head 
of  the  flexor  brevis  pollicis. 


185 

1 1 .  Musculo  -  spiralf  or  radial  nerve,  sends 
branches  to  the  triceps,  through  which  it  winds ;  a  . 
long  cutaneous  branch  to  the  elbow  ;  branches  to 
anconeus,  the  supinator  longus  and  extensors  ;  the 
anterior  or  radial  branch,  which  runs  along  the 
inner  side  of  the  supinator  radii  longus,  and  sends 
a  branch  to  the  integuments  of  the  thumb,  and 
another  to  the  dorsum  of  the  hand,  which  supplies 
the  index  and  middle  fingers,  and  communicates 
with  the  dorsalis  ulnaris  ;  and  a  deep  branch,  or 
posterior  interosseous,  which  supplies  by  superficial 
and  deep  branches  the  extensor  muscles,  and  ter- 
minates in  a  ganglion  on  the  wrist  beneath  the 
extensor  indicis. 

12.  Circumflex  nerve,  sends  branches  to  the 
deltoid  and  teres  minor  muscles,  skin,  and  shoulder- 
joint. 

TWELVE   PAIR   OF   DORSAL   NERVES. 

Posterior  branches  are  small,  and  pass  back- 
wards to  the  muscles  and  integuments  of  the  back 
and  loins. 

Anterior  branches^  or  intercostals.  First  is  the 
largest ;  it  contributes  partly  to  form  the  brachial 
plexus.  Second  and  third  run  backwards  and.  out- 
wards, and  at  the  angle  of  the  ribs  pass  between 
the  intercostal  muscles,  and  running  along  the 
lower  edge  of  each  rib  supply  the  surrounding 
muscles  :  opposite  the  axilla  they  send  ofi"  the 
intercosto-humeral  nerves,  of  which  one,  joining  a 


186 

branch  from  the  brachial  plexus,  forms  the  nerve 
ofWrisberg,  for  the  skin  of  the  arm,  and  the 
tenninal  branches  supply  the  muscles  and  skin 
upon  the  lateral  and  fore  part  of  the  thorax. 
Fourth  to  twelfth,  inclusive,  are  similar  to  the 
second  and  third  in  distribution,  supplying-  the 
intercostal  and  adjacent  muscles  :  the  two  last  go 
chiefly  to  the  diaphragm,  and  the  twelfth  sends  a 
branch  to  join  the  first  lumbar.  [All  the  inter- 
costals  are  connected  by  two  short  branches  to  the 
ganglia  of  the  sympathetic] 

FIVE  PAIR  OF  LUMBAR  NERVES. 

They  are  larger  than  the  dorsal,  and  like  them 
divide  into  posterior  and  anterior  branches. 

Posterior  branches  are  distributed  to  the  lumbar 
muscles  and  integuments. 

Anterior  branches  unite  in  the  substance  of  the 
psoas  muscle,  to  form  the  lumbar  plexus. 

LUMBAR    PLEXUS. 

1.  Ilio-inguinal,  from  the  first  nerve,  sends 
branches  to  the  abdominal  muscles,  a  cutaneous 
branch  to  the  integuments  on  the  outer  part  of  the 
thigh,  and  the  ilio-scrotal. 

2.  Ilio-hypogasiric,  from  the  first  nerve  to  the 
abdominal  muscles  and  skin  over  the  gluteal  region, 
and  to  the  skin  of  the  abdomen  above  the  pubes. 


187 

3.  Genito  crural,  from  the  second  neiTe,  sup- 
plies through  its  genital  branch  tlie  spermatic 
cord,  and  cremaster  :  through  its  crural  branches 
it  distributes  fiLaments  to  the  upper  part  of  the 
thigh,  communicating  with  the  middle  cutaneous. 

4.  External  cutaneous,  from  the  second  nerve,, 
sends  brunches  to  outer  and  back  part  of  thigh. 

5.  Anterior  crural  nerve,  formed  by  the  second, 
third,  and  fourth  nerves,  passes  beneath  Poupart's 
ligament,  and  divides  into  two  fasciculi.  The  su- 
perior fasciculus  sends  four  or  five  long  branches, 
which  pierce  the  fascia  lata,  and  descend  to  the 
knee :  some  of  them  accompany  the  saphena  vein ; 
the  deep  fasciculus  sends  external  muscular  branches 
to  the  vastus  externus,  rectus,  iliacus  internus 
mu&cles,  and  internal  branches  to  the  sartorius, 
vastus  internus,  andcrureus  :  branches  also  accom- 
pany the  femoral  artery,  near  to  the  knee,  the  in- 
ternal saphenous  nerve,  which  joins  the  saphena 
vein  at  the  knee,  lying  between  the  tendons  of  the 
gracilis  and  sartorius,  goes  on  to  the  inner  side 
of  the  foot,  sending  off  numerous  branches  to  the 
integuments. 

6.  Obturator  nerve,  from  the  third  and  fourth 
nerves,  sends  branches  to  the  obturator  externus, 
an  anterior  branch  to  the  adductor  longus,  pecti- 
neus,  and  gracilis,  and  a  posterior  branch  to  the 
adductor  magnus  and  brevis  muscles :  articular 
nerves  are  given  to  the  hip  and  knee  joints. 


188 

7.  Accessory-obturator  nerve,  inconstant,  divides 
into  branches  which  supply  the  hip-joint,  and  the 
pectineus. 

8.  Lumbosacral  nerve  proceeds  from  the  fourth 
and  fifth  lumbar  into  the  pelvis,  and  divides  into 
the  superior  gluteal  and  the  communicating  nerve: 
the  superior  gluteal  is  distributed  to  the  gluteus 
medius,  minimus,  and  tensor  fascise  femoris  mus- 
cles :  and  the  communicating  branch  joins  the 
first  sacral  nerve. 

FIVE  PAIR  OF  SACRAL  NERVES. 

Posterior  branches,  very  small,  to  muscles  and 
integuments. 

Anterior  branches,  very  large,  particularly  the 
three  superior  ;  these  five,  with  the  communicating 
branch  of  the  lumbo-sacral,  form  the  sacral  plexus. 

SACRAL   PLEXUS 

Sends  off  internal  or  pelvic  branches,  which  are 
named  Hasmorrhoidal,  Vesical,  Uterine,  and  Va- 
ginal.    External  branches. 

1.  Muscular  nerves,  to  the  pyriformis,obturator  in- 
temus,  gemelli,  quadratus  femoris  and  levator  anu 

2.  Lesser  sciatic  nerve,  to  the  gluteus  maximus 
and  integuments  of  the  buttock  and  thigh. 

3.  Posterior  cutaneous  nerve,  to  the  back  part  of 
the  thigh  and  leg. 


189 

4.  Pudic  nerve,  which  sends  an  inferior  branch 
to  the  muscles  of  the  perineum  and  to  the  scrotum  ; 
and  a  superior  branch  which  passes  along  the 
dorsum  of  the  penis  to  its  glans. 

5.  Great  sciatic  nerve,  sends  off  several  branches 
to  supply  the  semi-membranosus,  semi-tendinosus, 
biceps,  and  adductor  magnus  muscles,  also  the  hip 
joint ;  it  divides  at  the  upper  and  outer  part  of  the 
popliteal  space  into  two  branches — viz.,  the  pero- 
neal and  the  popliteal  nerves.  The  peroneal  nerve 
first  sends  off  the  communicans  peronei  of  the  leg, 
which  communicates  with  the  external  saphenous 
nerve ;  it  next  gives  off  the  musculo-cutaneous 
nerve,  which  divides  into  an  internal  and  an  ex- 
ternal branch,  the  former  being  distributed  to  the 
integuments  of  the  inner  side  of  great,  and  con- 
tiguous sides  of  second  and  third  toes,  the  latter  to 
the  outer  side  of  third,  the  whole  of  the  fourth  and 
the  inner  side  of  the  fifth  toes ;  and  lastly,  the 
anterior  tibial,  which  winds  round  the  head  of  the 
fibula,  and  supplies  the  integuments  on  the  anterior 
part  of  the  leg,  the  tibialis  anticus,  the  extensor 
digitorum  longus,  the  extensor  poUicis,  and  the 
extensor  digitorum  brevis  muscles,  and  terminates 
at  the  first  interosseal  space  by  communicating 
with  the  plantar  nerves,  having  first  supplied  the 
inner  interosseous  muscle.  The  popliteal  division 
of  the  great  sciatic  first  sends  off"  the  external 
saphenous  nerve,  and  branches  to  the  gastrocne- 


190 

mius,  soleus,  plantaris,  and  popliteus  muscles.  At 
the  lower  border  of  the  popliteus  muscle  it  becomes 
the  posterior  tibial,  which  supplies  the  tibialis 
posticus,  flexor  longus  digitorum,  and  flexor  longus 
pollicis  ;  it  finally  divides  into  the  internal  and  ex- 
ternal plantar  nerves  ;  the  former  sending  branches 
to  the  three  and  a  half  inner  toes,  to  the  abductor 
pollicis,  flexor  brevis  pollicis,  and  two  inner  lum- 
bricales;  the  latter  a  supei*ficial  branch  to  the  little 
toe  and  outer  side  of  the  fourth  toe,  and  a  deep 
branch  to  all  the  muscles  of  foot  except  those 
previously  described. 

SYMPATHETIC   OR  GANGLIONIC   SYSTEM   OF 
NERVES. 

The  sympathetic  nerves,  characterized  by  their 
grey  colour  and  by  their  numerous  ganglia,  forma 
system,  which  communicates  with  all  the  cerebral 
nerves,  except  the  three  nerves  of  special  sense 
[viz.,  the  olfactory,  the  optic,  and  the  auditory] 
and  with  all  the  spinal  nerves.  In  the  chest  and 
abdomen  large  plexuses  are  formed  in  front  of  the 
vertebral  column. 

THE    CERVICAL   GANGLIA 

Are  three  in  number. 

Superior  cervical  ganglion  extends  from  the  first 


191 

to  llie  third  cervical  vertebra,  and  sends  off — 1. 
Two  superior  branches,  which  ascend  along  with 
the  carotid  artery  in  the  carotid  canal  to  the  caver- 
nous sinus,  where  they  communicate  with  the  sixth 
or  abducens  nerve,  and  with  the  Vidian  nerve. 
2.  Descending  or  inferior  iihiments,  which  join  the 
laryngeal  and  pneumogastric  nerves,  the  superior 
cardiac  nerve,  and  the  middle  cervical  ganglion,  if 
it  exists;  if  not,  they  join  the  inferior  ganglion.  3. 
Internal  branches,  which  unite  with  the  pharyn- 
geal plexus.  4.  External  branches,  to  join  the  supe- 
rior cervical  nerves.  5.  Anterior  branches,  which 
unite  with  the  pneumogastric  and  facial  nerves,  and 
form  a  plexus  around  the  carotid  artery,  from 
which  branches  proceed  along  the  external  carotid 
and  its  divisions. 

Middle  cervical  ganglion,  placed  opposite  the 
fifth  or  sixth  cervical  vertebrse,  is  sometimes  absent ; 
when  present  it  sends  branches  to  unite  with  the 
vagus  and  ceiTical  nerves,  branches  to  join  the 
cardiac  nerves,  and  filaments  to  the  inferior  thy- 
roid artery. 

Inferior  cervical  ganglion  is  situated  between  the 
transverse  process  of  the  last  cervical  vertebra 
and  the  neck  of  the  first  rib  ;  it  sends  branches  to 
the  phrenic  nerve,  brachial  plexus,  subclavian 
artery  and  its  ramifications,  and  branches  to  the 
inferior  cardiac  nerve. 

Cardiac  nerves  are  three   in   number,  and   are 


193 

named  superior,  middle,  and  inferior.  1.  Superior 
Cardiac  Nerves  arise  by  two  or  three  filaments 
from  the  superior  cervical  ganglia,  communicate 
with  the  vagus  and  laryngeal  nerves,  and  with  the 
middle  and  inferior  cervical  ganglion,  pass  along 
the  coats  of  the  arteria  innominata  on  the  right 
side,  and  between  the  left  carotid  and  left  subcla- 
vian on  the  left  side  to  the  aorta,  and  here  com- 
municate with  the  recurrent  nerves,  and  with 
the  middle  and  inferior  cardiac  nerves,  and  the 
cardiac  ganglion  or  plexus.  2.  Middle  Cardiac 
Nerves.  That  of  the  right  side  is  generally  the 
largest ;  on  the  left  side  it  is  sometimes  wanting. 
They  enter  the  thorax  anterior  to  the  subclavian 
artery,  are  joined  by  branches  from  the  pneumo- 
gastric  and  recurrent  nerves,  and,  passing  along 
the  arteria  innominata,  terminate  in  the  cardiac 
ganglion  and  plexus.  3.  Inferior  Cardiac  Branches. 
The  right  descends  along  the  arteria  innominata 
to  the  fore  part  of  the  arch  of  the  aorta,  and  termi- 
nates in  the  anterior  cardiac  plexus  :  some  branches 
pass  between  the  aorta  and  pulmonary  artery  to 
the  cardiac  ganglion  ;  on  the  left  these  nerves  ac- 
company the  subclavian  artery,  and  partly  join  the 
middle  cardiac  nerve  and  partly  the  cardiac  plexus. 
Cardiac  plexus,  or  Cardiac  Ganglion,  is  situated 
behind  the  ascending  aorta,  near  its  origin,  in  front 
of  the  trachea  and  right  pulmonary  artery ;  it  con- 
sists of  a  plexus  of  nerves   formed  by  the  cardiac 


193 

nerves  of  the  opposite  sides  and  branches  of  the 
eighth  pair  and  recurrent.  In  the  meshes  of 
this  plexus  several  small  ganglia  are  enclosed. 
Branches  proceed  from  this  plexus  to  the  coronary 
and  pulmonary  vessels,  to  the  aorta  and  vena  cava, 
and  to  the  substance  of  the  heart  itself. 
•  Thoracic  Ganglia  are  twelve  on  each  side,  some- 
times only  eleven,  the  last  cervical  and  first  dorsal 
being  united.  1.  Branches  to  the  mediastinum, 
which  ramify  on  the  aorta  and  adjacent  vessels, 
and  communicate  with  the  pulmonary  plexus.  2. 
Great  Splanchnic  Nerve,  is  formed  by  distinct 
roots,  from  the  6th,  7th,  8th,  and  9th  ganglia; 
uniting  on  the  9th  dorsal  vertebra  into  one  cord, 
it  enters  the  abdomen  through  the  crus  of  the  dia- 
phragm, and  expands  into  the  semilunar  ganglion. 
3.  Lesser  Splanchnic  Nerve,  arises  by  two  roots 
from  the  10th  and  11th  ganglia;  uniting  on  the 
side  of  the  last  dorsal  vertebra,  it  enters  the  abdo- 
men through  the  crus  of  the  diaphragm,  and  ends 
partly  in  the  renal  plexus  and  partly  in  the  ca3liac 
plexuses.  4.  Smallest  Splanchnic  Nerve,  arises 
from  the  12th  ganglion  and  ends  in  the  renal  and 
coeliac  plexuses.  Branches  from  the  first  and 
second  ganglion  go  to  the  cardiac  plexus ;  branches 
from  the  third  and  fourth  to  the  pulmonary  plexus. 
Semilunar  Ganglia  are  situated  on  the  dia- 
phragm, partly  on  the  aorta,  and  on  each  side  of 
the  coeiiac  axis,  and  above  and  behind  the  supra- 


194 

renal  capsules.  They  are  the  largest  ganglia  of 
the  sympathetic;  several  nervous  filaments,  on 
which  small  ganglia  are  placed,  pass  from  one  to 
the  other  surrounding  the  coeliac  axis,  forming  a 
plexus,  called  the 

Sola7'  Plexus,  which  is  situated  behind  the  sto- 
mach, above  the  pancreas,  and  in  front  of  the  aorta. 
It  gives  off — 1.  Branches  in  various  directions,  ac- 
companying the  blood-vessels,  forming  plexuses 
around  each,  and  named  accordingly,  hepatic, 
splenic,  and  gastric,  and  these  communicate  with 
the  eighth  pair.  2.  Branches  descending  in  front 
of  the  aorta,  which  subdivide  at  the  renal  and 
mesenteric  arteries,  accompanying  them,  and  form- 
ing plexuses,  named  accordmgly,  renal,  superior 
and  inferior  mesenteric,  and  into  each  of  these 
branches  of  the  lumbar  ganglia  enter. 

Renal  Plexus  receives  the  lesser  splanchnic 
nerves  ;  from  it  descends  the  spermatic  plexus, 
which  goes  to  the  testicle  in  the  male,  and  to  the 
ovary  and  uterus  in  the  female. 

Inferior  Mesenteric  Plexus  sends  branches  which 
descend  to  the  brim  of  the  pelvis,  unite  with  others 
from  the  lumbar  ganglia,  and  form  a  plexus  around 
the  internal  iliac  artery  and  its  branches,  named 
hypogastric  plexus.  It  is  joined  by  numerous 
filaments  from  the  lumbar  and  sacral  ganglia  of 
the  sympathetic,  and  communicates  with  the  pel- 
vic branches  of  the  sacral  plexus. 


195 

Lumbar  Ganglia  arc  five  on  each  side,  sometimes 
only  three  or  four.  1.  Filaments  to  anterior 
branches  of  lumbar  spinal  nerves.  2.  Filaments  to 
assist  in  forming  the  several  abdominal  plexuses. 

Sacral  Ganglia  are  three  or  four  in  number.  1. 
Filaments  to  sacral  nerves.  2.  Filaments  to  hypo- 
gastric and  pelvic  plexuses.  3.  A  small  branch 
from  the  last  ganglion,  which  passes  in  front  of 
the  coccyx,  there  forming  with  its  fellow  the 

Ganglion  Impar,  which  sends  branches  to  the 
coccygeus,  levator,  and  sphincter  ani  muscles. 


THE  THOEAX  AND  ITS  CONTENTS. 

The  thorax  is  bounded  anteriorly  by  the  sternum 
and  cartilages  of  the  ribs,  posteriorly  by  the  verte- 
brie  and  the  ribs,  and  on  each  side  by  the  shafts  of 
the  ribs  and  the  mtercostal  muscles.  Its  upper 
opening  is  transversely  oval,  and  allows  the  exit 
and  entrance  of  vessels,  nerves,  and  muscles,  to 
and  from  its  cavity ;  its  mfcrior  opening,  or  cir- 
cumference, is  much  larger,  and  closed  by  the  dia- 
phragm. 

The  thorax  contains  the  heart  and  lungs,  and 
also  several  vessels,  nerves,  glands,  i&c. 

o2 


196 


THE   PLEURiE 


Are  two  serous  membranes,  one  on  each  side, 
and  distinct  from  each  other,  which  cover  the  inner 
surface  of  the  thorax,  and  are  reflected  upon  the 
outer  surfaces  of  the  parts  contained  in  its  cavity. 
That  portion  of  the  pleura  which  lines  the  thorax 
is  called  the  parietal  layer,  and  that  which  lines  the 
contained  parts  the  visceral  layer.  Each  pleura 
can  be  traced  in  the  following  manner ; — From  the 
posterior  surface  of  the  sternum  it  passes  back- 
wards until  it  meets  with  the  anterior  surface  of 
the  pericardium,  along  the  side  of  which  it  passes 
to  the  anterior  surface  of  the  root  of  the  lung ; 
from  this  it  passes  upon  the  lung,  and  is  reflected 
over  the  entire  surface  of  the  organ,  until  it  arrives 
at  the  posterior  surface  of  its  root  and  of  the  peri- 
cardium, from  whence  it  passes  upon  the  sides  of 
the  bodies  of  the  vertebrae,  reaching  as  high  as  the 
transverse  process  of  the  sixth  cervical  vertebra  on 
the  right  side,  the  seventh  on  the  left,  and  descend- 
ing to  the  diaphragm,  the  thoracic  aspect  of  which 
it  covers  ;  it  finally  lines  the  ribs  and  intercostal 
muscles,  until  it  arrives  at  the  portion  which  was 
opened,  and  which  corresponds  to  the  posterior 
aspect  of  the  sternum. 

Ligamentum  latum  pulmonis  (one  on  each  side)  is 
merely  a  double  triangular  layer  of  pleura,  formed 
by  the  reflection  of  the  membrane  from  the  lower 


197 

edge  of  the  root  of  the  lung  upon  the  vessels  from 
the  heart. 

ANTERIOR  MEDIASTINUM, 

A  triangular  interspace  between  the  right  and 
left  pleura  behind  the  sternum ;  the  base  is  formed 
by  the  sternum,  the  sides  by  the  separated  pleurae, 
and  the  apex  corresponds  to  the  anterior  surface  of 
the  pericardium,  where  the  pleurae  separate  to 
enclose  this  bag.  Thus  formed,  it  contains  the 
origins  of  the  sterno-hyoid  and  sterno-thyroid 
muscles,  the  remains  of  the  thymus  gland  with  its 
vessels,  lymphatic  glands  and  absorbents,  the  tri- 
angularis sterni  muscles,  loose  cellular  tissue,  and 
the  internal  mammary  artery  of  the  left  side. 

MIDDLE   MEDIASTINUM 

Is  of  oval  shape,  and  is  formed  by  the  reflection 
of  the  pleurae  uj^on  the  sides  of  the  pericardium ; 
it  consequently  contains  this  bag  and  its  contents 
—viz.,  the  heart,  with  its  vessels  ;  also  the  phrenic 
nerves  and  the  bifurcation  of  the  trachea. 

POSTERIOR   MEDIASTINUM 

Is  formed  by  the  reflection  of  the  pleurae  upon 
the  sides  of  the  bodies  of  the  vertebrae ;  it  is  of  tri- 
angular form,  the  apex,  anterior,  corresponding  to 
the  posterior  surface  of  the  pericardium,  the  sides 
formed  by  the  pleurae,  and  the  base  represented  by 


108 

the  anterior  surfaces  of  the  bodies  of  the  vertebras ; 
it  extends  from  the  third  to  the  tenth  dorsal  verte- 
bra, and  contains  the  following  structures  : — the 
oesophagus  and  pneumogastric  nerves,  the  thoracic 
duct,  the  vena  azygos,  the  thoracic  aorta,  lym- 
phatic glands,  absorbents,  bronchial  and  oesopha- 
geal arteries,  the  right  aortic  intercostal  arteries, 
and  loose  cellular  tissue. 

THE    LUNGS. 

Are  two  soft,  spongy,  vascular  organs,  one  con- 
tained in  each  side  of  the  cavity  of  the  chest. 
Each  lung  resembles  a  cone,  with  that  side  corre- 
sponding to  the  median  line  truncated;  the  base, 
concave,  corresponds  to  the  diaphragm ;  the  obtuse 
rounded  apex  rises  in  the  neck,  a  little  above  the 
level  of  the  first  rib  ;  the  external  convex  surface 
corresponds  to  the  internal  concave  surface  of  the 
thoracic  parietes,  and  the  flat  or  truncated  surface 
corresponds  to  the  mediastina.  The  posterior  edge 
of  the  lung  is  thick  and  rounded,  whilst  the  ante- 
rior is  thin  and  irregular.  Each  lung  is  divided 
into  two  lobes,  which  are  separated  from  each  other 
by  fissures ;  a  little  above  the  centre  of  each  is  the 
root  formed  by  the  pulmonary  vessels  and  bron- 
chus, connected  to  each  other  by  cellular  tissue, 
and  invested  by  the  pleura.  The  bronchus  is 
situated  posterior  and  superior  to  the  pulmonary- 
vessels  ;  the  two  pulmonary  veins  are  placed  ante- 


199 

rior  and  inferior  to  the  artery  and  bronchus,  and 
the  pulmonary  artery  is  placed  between  the  bron- 
chus and  the  pulmonary  veins,  but  behind  the  pul- 
monary veins  and  before  the  bronchus.  On  the 
left  side,  the  bronchus,  more  oblique  than  its  fellow, 
descends  near  the  root  of  the  lung  so  as  to  lie  be- 
tween the  artery  and  vein.  The  root  of  each  lung 
has  anterior  to  it  the  phrenic  nerve  and  filaments 
of  the  pneumogastric  nerve,  posterior  to  it  the 
pulmonic  plexus.  The  root  of  the  right  lung  has 
the  vena  azygos  arching  over  it. 

The  right  and  left  lungs  differ  from  each  other 
in  some  unimportant  particulars  :  the  right  lung  is 
broader  and  shorter  than  the  left,  and  consists  of 
three  lobes,  separated  by  two  fissures  ;  the  right 
also  ascends  higher  in  the  neck,  and  the  anterior 
edge  of  the  left  presents  a  notch  where  it  corre- 
sponds to  the  apex  of  the  heart. 

The  structure  of  the  lungs  consists  of  numerous 
small  lobules,  which  are  the  alveolar  dilatations  of 
the  smallest  bronchial  tubes  :  the  lobules  are  held 
together  by  blood-vessels  and  interlobular  tissue  ; 
they  vary  from  half  a  line  to  a  line  in  diameter, 
and  do  not  communicate  with  one  another,  except 
through  the  medium  of  the  air  tubes.  The  bron- 
chial tubes  enter  the  lungs,  and  by  frequent  divi- 
sions rapidly  diminish  in  size,  until  they  may  be 
traced  to  about  half  a  line  in  diameter,  beyond 
which  the  tubes  are  entirely  membranous.  A  little 


200 

beyond  this  stage  they  arc  termed  lobular  passages, 
and  then  terminate  in  an  irregularly  pouched  dila- 
tation, the  air  cell  or  alveolus.  The  cells  are  lined 
with  squamous  epithelium,  which  may  be  traced 
through  the  lobular  passages  as  far  as  the  minute 
bronchi,  which  are  lined  with  cylindrical  ciliated 
epithelium.  Between  the  air  cells  is  spread  the 
capillary  network  of  the  pulmonary  vessels,  which 
are  seen  to  come  from  an  arterial  circle  close  to  the 
alveolus.  The  branches  of  the  pulmonary  artery 
accompany  the  divisions  of  the  bronchi  to  their  re- 
mote ramifications,  and  ultimately  open  into  the 
pulmonary  veins.  The  bronchial  arteries  supply 
nourishment  to  the  bronchi  and  the  parenchy- 
matous structure  of  the  lung.  The  lymphatics 
enter  the  bronchial  glands,  and  its  nerves  come 
from  the  anterior  and  posterior  pulmonary  plexus 
of  the  pneumogastric,  joined  by  branches  from  the 
dorsal  sympathetic  system. 

TRACHEA   AND    ITS   RAMIFICATIONS. 

The  windpipe,  or  trachea,  is  a  cylindrical  tube, 
about  four  and  a  half  inches  in  length,  extending 
from  the  cricoid  cartilage  of  the  larynx  to  the  level 
of  the  third  dorsal  vertebra.  It  consists  of  from 
seventeen  to  twenty  incomplete  fibro-cartilaginous 
rings,  truncated  behind,  and  connected  to  each 
other  by  an  elastic  membrane ;  about  the  posterior 


201 

fourth  of  each  ring  is  deficient,  and  its  place  is  sup- 
plied by  fibrous  membrane  and  unstriped  or  involun- 
tary muscular  fibre. 

Opposite  the  third  dorsal  vertebra  the  trachea 
divides  into  the  right  and  left  bronchi ;  the  right 
bronchus,  larger  than  the  left,  runs  transversely 
into  the  root  of  the  lung,  and  divides  into  three 
branches;  the  left  bronchus  passes  obliquely 
beneath  the  arch  of  the  aorta  to  the  root  of  the 
left  lung,  and  divides  into  two  branches. 

The  bronchi  consist  of  cartilaginous  rings,  but  as 
these  tubes  advance  into  the  substance  of  the  lung 
they  diminish  in  size  and  firmness,  until  their  place 
is  supplied  by  fibrous  tissue,  involuntary  muscular 
fibres,  which  tissue  also  disappears,  and  at  length 
nothing  remains  but  the  mucous  membrane,  which 
terminates  in  the  air-cells,  upon  which  ramify  the 
ultimate  branches  of  the  pulmonary  artery  and  the 
commencing  radicles  of  the  pulmonary  veins. 

The  mucous  membrane  is  pale,  closely  connected 
with  the  deeper  structures,  and  covered  with  colum- 
nar ciliated  epithelium. 

HEART   AND   PERICARDIUM. 

The  pericardium  consists  of  two  layers,  an  outer, 
or  proper  fibrous  layer,  and  an  inner,  or  serous 
layer.  It  is  of  conical  form,  the  base  below  con- 
nected to  the  central  division  of  the  cordiform 
tendon  of  the  diaphragm,  the  apex  above  corr©- 


203 

sponding  to  the  great  vessels  at  the  base  of  the 
heart,  along  the  outer  coats  of  which  the  fibrous 
layer  is  gradually  lost ;  it  is  connected  laterally  to 
the  pleura  and  to  the  pulmonary  vessels ;  the 
phrenic  nerves,  one  on  each  side,  run  in  close  con- 
tact with  it  to  the  diaphragm.  Upon  laying  open 
the  cavity  of  the  pericardium,  the  serous  layer  is 
exposed,  and,  like  all  serous  membranes,  it  consists 
of  two  portions — a  parietal  layer,  which  lines  the 
inner  surface  of  the  fibrous  pericardium,  and  a  vis- 
ceral layer,  which  lines  the  outer  surface  of  the 
heart  and  great  vessels.  When  the  pericardium  is 
fully  opened,  we  bring  into  view,  covered  by  the 
serous  membrane,  the  right  auricle,  the  vena  cava 
superior,  the  left  auricular  appendix,  the  right  ven- 
tricle, the  tip  of  the  left  ventricle  (which  forms  the 
apex  of  the  heart),  the  aorta,  t lie  pulmonary  artery, 
and  the  anterior  branches  of  the  coronary  vessels, 
with  the  ramifications  of  the  cardiac  nerves. 
Upon  turning  up  the  heart  its  posterior  surfiice  will 
be  brought  into  view,  presenting  the  left  auricle 
(proceeding  to  which,  on  cither  side,  are  the  pul- 
monary veins)  and  the  left  ventricle. 

The  serous  membrane  may  be  traced  in  the 
following  manner : — After  having  lined  the  fibrous 
pericardium  it  is  reflected  on  the  superior  cava  and 
the  aorta,  and  the  pulmonary  artery,  as  these 
vessels  are  passing  through  the  fibrous  membrane, 
ascending  highest,  however,  upon  the  aorta  ;  in- 


203 

feriorly  it  is  partly  reflected  around  the  inferior 
cava,  as  this  vessel  pierces  the  fibrous  pericardium 
to  enter  the  right  auricle,  and  laterally  it  is  re- 
flected upon  the  pulmonary  veins  as  these  vessels 
pierce  the  fibrous  pericardium  to  enter  the  left 
auricle;  from  these  different  points  it  reaches  the 
surface  of  the  heart,  which  it  completely  covers. 

The  heart  is  a  hollow  muscular  organ  of  conical 
shape,  situated  obliquely  between  the  lungs,  its 
base  being  superior,  posterior,  and  to  the  right  side, 
its  apex  pointing  towards  the  cartilage  of  the  sixth 
rib  of  the  left  side.  The  axis  of  the  heart  is 
obliquely  from  right  to  left,  and  from  behind  for- 
wards. It  is  retained  in  its  situation  by  the  great 
vessels  and  tj^e  reflections  of  the  serous  membrane. 

The  heart  consists  of  four  cavities,  two  auricles 
and  two  ventricles ;  the  auricles  are  separated  from 
each  other  by  a  partition,  called  septum  auricula- 
rum,  the  ventricles  by  the  septum  vcntriculorum. 
We  shall  examine  these  cavities  in  the  order  of  the 
circulation. 

The  right  auricle  is  placed  between  the  two 
venae  cavjB,  the  blood  conveyed  by  which  it  receives 
and  transmits  to  the  right  ventricle  ;  the  small  loose 
portion  is  called  the  auricular  appendix,  and  the 
portion  between  the  cavse  the  sinus  of  the  auricle. 
Upon  laying  open  this  auricle,  by  a  perpendicular 
cut  from  the  superior  cava  to  within  a  few  lines  of 
the  entrance  of  the  inferior  cava,  and  by  a  second 


204 

cut  from  the  centre  of  this  at  right  angles  towards 
the  auricular  appendix,  the  following  parts  present 
themselves : — 

Tuberculum  Loweri  is  seen  mainly  in  the  heart 
of  the  lower  mammalia,  between  the  orifices  of  the 
two  cavae. 

Septum  aiiricularum,  a  membrano-muscular  par- 
tition separating  this  auricle  from  the  left. 

Fossa  ovalis,  an  oval  depression  in  the  septum, 
which  marks  the  situation  of  the  foramen  ovale,  or 
the  oval  communication  which  existed  between  both 
auricles  in  the  foetus.  The  edges  of  this  fossa  pre- 
sent a  thickened  margin,  the  annul  is  ovalis,  the 
anterior  part  of  which  is  named  the  left  or  anterior 
limbus  of  the  fossa  ovalis,  and  the  posterior,  the 
right  or  posterior  limbus.  This  fossa  and  its  limbi 
exist  in  the  right  aspect  of  the  septum,  on  account 
of  the  valve  in  the  foetus,  which  is  destined  to  close 
the  opening  between  the  two  auricles,  when  the 
pulmonic  circulation  is  established,  being  situated 
in  the  left  auricle,  and  being  applied  to  the  foramen 
on  its  left  aspect.  We  accordingly  find  the  left 
aspect  of  the  septum  auricularum  nearly  smooth. 

Eustachian  valve,  a  semilunar  fold  of  the  lining 
membrane,  attached  by  one  cornu  to  the  anterior 
limbus  of  the  fossa  ovalis,  and  continued  around 
the  anterior  aspect  of  the  inferior  vena  cava,  to 
reach  the  posterior  limbus  of  the  fossa  ovalis,  to 
which  it  is  attached  by  its  inferior  cornu. 


205 

Muscull  pedinati,  the  muscular  bands  situated 
in  the  auricular  appendix. 

Openings  of  the  Venoe  Cavoe. — The  superior  cava 
opens  at  the  upper  and  front  part  of  the  auricle,  its 
direction  being  downwards,  forwards,  and  inwards ; 
the  inferior  cava  opens  beneath,  in  a  direction  up- 
wards, backwards,  and  inwards. 

Opening  of  the  Coronary  Vein  is  situated  be- 
tween the  Eustachian  valve  and  the  right  ventricle, 
and  is  guarded  by  a  semilunar  valve  (the  coronary 
valve). 

Opening  of  the  Auricular  Appendix  is  small  and 
circular,  and  exists  where  this  portion  of  the  auricle 
joins  the  sinus. 

Foramina  Thehesii,  small  orifices  on  different 
parts  of  the  auricle,  the  openings  of  small  veins 
from  the  muscular  structure  of  the  heart. 

Bight  Auriculo-ventricular  opening,  the  large 
opening  by  which  the  auricle  communicates  with 
the  ventricle,  the  boundaries  of  each  cavity  being 
marked  by  a  white  line. 

Right  Ventricle,  of  conical  form,  is  joined  by 
its  basis  to  the  right  auricle,  its  apex  being  above 
the  apex  of  the  heart,  in  consequence  of  the  apex 
of  this  organ  being  formed  by  the  left  ventricle. 

Septum  ventriculorum,  a  thick  muscular  partition 
which  separates  one  ventricle  from  the  other,  but 
belongs  chiefly  to  the  left. 

Carnece  columnce,  the  muscular  projections  in  tho 


206 

interior  of  the  ventricle,  which  give  it  its  irregular 
appearance ;  three  larger  than  the  rest  are  called 
mnsculi  papillares,  to  which  are  attached  the 
chordae  tendincse. 

C/iordce  tendinece,  the  delicate  but  strong  tendi- 
nous chords  which  are  connected  by  ons  extremity 
to  the  carneas  columns),  and  by  the  other  to  the 
tricuspid  valve. 

Conus  arteriosus,  the  smooth  surface  of  the  ven- 
tricle towards  the  pulmonary  opening. 

Tricuspid  Valve,  three  triangular  duplicatures 
of  the  lining  membrane  of  the  heart,  strengthened 
by  the  chordae  tendineae  which  pass  from  their 
apices  to  their  bases.  These  triangular  valves  are 
attached  by  their  bases  to  the  right  auriculo-ven- 
tricular  opening,  and  by  their  apices  to  the  chordae 
tendincfB,  and  prevent  the  regurgitation  of  the 
blood  from  the  ventricle  into  the  auricle,  by  closing 
the  opening  of  communication  between  both  cavi- 
ties when  the  ventricle  contracts. 

Orifice  of  the  Pidmonary  Artery  is  situated  at  the 
left  extremity  of  the  base  of  the  ventricle,  close  to 
the  right  auriculo-ventricular  opening,  which  is 
situated  inferior,  posterior,  and  to  its  right,  and 
separated  from  the  mouth  of  the  artery  by  the 
largest  cusp  of  the  tricuspid  valve. 

Pulmonary  Semilunar  Valves  extend  from  the 
line  of  junction  of  the  pulmonary  artery  and  right 
ventricle  into   the  cavity  of  the  former.     These 


207 

three  valves  are  duplicaturcs  of  the  lining  membrane, 
and  are  attached  by  their  convex  edges  to  the  roots 
of  the  pulmonary  artery  ;  their  free  concave  margins 
presenting  in  the  centre  a  small  tubercle,  called 
corpus  AmntiL  These  valves,  when  the  blood 
passes  from  this  ventricle  into  the  pulmonary  artery, 
are  pressed  down,  and  thus,  by  closing  the  opening, 
prevent  a  reflux  of  the  blood  back  again  into  the 
ventricle. 

Left  auricle  is  placed  at  the  upper  and  back 
part  of  the  heart,  and  is  of  quadrilateral  form.  It 
is  smaller  than  the  right  auricle,  and  receives,  at 
its  four  angles,  the  openings  of  the  pulmonary 
veins  ;  its  parietes  are  much  thicker  than  the  right ; 
its  auricular  appendix  smaller,  but  the  musculi  pec- 
tinati  are  the  stronger :  with  the  exception  of  the 
auricular  appendix,  its  inner  surface  is  smooth,  and 
it  communicates  with  its  corresponding  ventricle 
by  the  left  auriculo-ventricular  opening,  which  is  sit- 
luited  inferior  to  the  opening  of  the  auricular  appen- 
dix, and  is  marked  by  a  whitish  line.  The  septum 
auricularum  presents  towards  this  auricle  a  smooth 
aspect,  from  circumstances  already  explained. 

Left  ventricle  is  longer,  stronger,  and  smaller 
than  the  right;  from  its  greater  length  it  forms  the 
apex  of  the  heart;  from  its  greater  strength  it  is  of 
power  sufficient  to  propel  the  arterial  blood  through 
the  aorta  and  its  ramifications.  We  consequently 
find  the  carneae  columnae,  the  chorda?  tcndinea3,  tho 


208 

bicuspid,  or  mitral  valve,  the  parletes  of  the  cavity, 
the  aorta,  which  arises  from  it,  and  the  semilunar 
valves,  with  their  corpora  Arantii,  which  guard  the 
opening  of  this  vessel,  much  stronger  than  in  the 
right  division  of  the  heart. 

The  left  auriculo-ventricular  opening,  and  the 
mouth  of  the  aorta,  are  situated  at  the  base  of  this 
cavity,  and  are  close  to  each  other,  the  aortic  open- 
ing being  anterior,  and  both  being  separated,  as  in 
the  right  ventricle,  by  the  larger  divit^ion  of  the 
bicuspid  valve.  With  the  exception  of  the  pecu- 
liarities just  mentioned,  the  left  auricle  and  ven- 
tricle are,  in  their  anatomical  configuration,  similar 
to  the  right,  and  the  several  valves,  muscular  emi- 
nences, tendons,  cords,  &c.,  serve  similar  purposes : 
the  septum  ventriculorum  belongs  chiefly  to  the 
left  ventricle. 


ARTERIES.  ^ 

THE    AORTA 

Is  divided  into  three  portions — viz.,  the  arch  of 
aorta,  the  thoracic  aorta,  and  the  abdominal  aorta. 

THE   ARCH    OF   THE   AORTA 

Is  divided  into  an  ascending,  transverse,  and 
descending  portion.     It  sends  off  five  branches. 

A.  Arteria  coronaria  dextra,  which  sends  a 
branch  to  the  right  auricle,  a  branch  to  the  anterior 


209 

part  of  the  right  ventricle,  and   a  branch  to  the 
posterior  part  of  the  right  ventricle. 

B.  Arteria  coronaria  sinistra^  which  sends  a 
branch  to  the  left  auricle,  and  a  branch  to  the  left 
ventricle. 

C.  Arteria  innominata,  H  inch  long,  which  di- 
vides behind  the  right  sterno-clavicular  joint  into 
the  right  carotid  and  right  subclavian  arteries. 

D.  Left  carotid  artery. 

E.  Left  subclavian  artery, 

THE    COMMON    CAROTIDS 

Ascend  the  neck  in  the  same  sheath  with  the  in- 
ternal jugular  vein  and  pneumogastric  nerve,  and 
divide  opposite  the  upper  border  of  the  thyroid 
cartilage  into  two  branches. 

A.  External  carotid  artery. 

B.  Internal  carotid  arteiij. 

TH^    EXTERNAL   CAROTID 

Sends  off  thoc  branches,  viz. : — 

A.  Superior  thyroid,  which  sends  off— 1st,  a 
hyoid  branch  ;  2nd,  a  sterno-mastoid  branch ; 
3rd,  a  superior  laryngeal  branch;  4th,  a  thyroid 
branefe^,  and  5th,  a  crico-thyrmd  branch. 

B.  Lm(7Ma/,  which  sends  off — 1st,  a  hyoid  branch; 
2nd,^he  dorsalis  linguae  artery  ;  3rd,  the  sublin- 
gual'artery ;  and  4th,  the  ranine  artery. 

C.  Facial,  which  sends   off— 1st,   the  inferior 

P 


210 

palatine;  2nd,  the  tonsillar;  3rd,  the  glandular;  ' 
^  4th,  the  submental;  5th  the  inferior  labial;  6th, 
the  inferior  coronary ;  7th,  superior  coronary ;  8tb, 
the  lateral  nasal ;  and  9th,  the  angular.    ^5>,      ^^^    ,^ 

D.  Occipital,  which  gives  off*  muscular  branches, 
superior  sterno-mast044^  auricular,  princeps  cervi- 
cis,  posterior  meningeal,  and  the  terminal  branches, 
of  wliich  one  enters  the  mastoid  foramen ;  the  others 
ramify  in  the  scalp. 

E.  Posterior  auricular,  which  gives  off  the  mus- 
cular, the  glan4»i«fc«s  and  the  stylo-mastoid. 

F.  Ascending  pharyngeal,  which  gives  off"  the 
pharyngeal  branches  and  the  meningeal  branches. 
^  G.  Transverse  facial,  *#«ietime»a  branch  of  the 
temporal. 

'^  H.  Superficial  temporal,  which  gives  off"  the  an- 
terior auricular,  tho  apttealiir  branohoi,  the  middle 
temporal,  the  posterior  and  anterior  temporal. 

I.  Internal  maxillary,  which  gives  off,  in  the 
first  part  of  its  course,  the  tympanic  which  enters 
the  fissura  Glaseri,  the  arteria  meningea  media, 
which  enters  the  foramen  spinosum,  the  inferior 
maxillary  or  dental  which  enters  the  dental  fora- 
men, and  the  arteria  meningea  parva  which  enters 
the  foramen  ovale  |  from  the  second  part  of  the 
artery  which  lies  among  the  pterygoid  muscles,  are 
given  off*,  the  deep  anterior  and  posterior  temporal, 
the  pterygoid,  the  masseteric,  and  the  buccal  |  and 
from  the  third  part  of  the  artery  which  lies  in  the 


211 

spheno-maxiUary  fossa  arc  derived  the  following, 
which  aH  pass  through  bony  foramina,  the  Mipogior 
alveolar,  the  infra-orbital,  the  descending  palatine, 
the  Vidian,  the  pterygo-palatine,  and  the  spheno- 
palatine or  nasal. 

THE    INTERNAL   CAROTID 

Supplies  no  vessels  in  the  neck,  but  in  its  passage 
through  the  petrous  portion  of  the  temporal  bone, 
gives  off — 

A.  Tlie  tijmpanic. 

B.  TJie  artence  receptacuU,  or  vessels  to  the 
cavernous  sinus. 

C.  The  anterior  meningeal. 

Opposite  the  anterior  cUnoid  process  it  divides 
into — 

A.  Ophthalmic  aii.ery,vf\i\Q\\  sends  off— 1st,  the 
lachrymal;  2nd,  the  centralis  retyifE;  3rd,  the  supra- 
orbital; 4th,  the  ciliary  fefftiieftes ;  5th,  the  mus- 
cular; 6th,  the  posterior  ethmoidal;  7th,  the 
anterior  ethmoidal ;  8th,  the  palpebral;  9tli,  the 
nasal;  10th,  the  frontal;  an^  11th,  the  anterior 
ciliary.  «  ^    -  ^   • 

B.  Posterior  communicating  dxtery. 

C.  Anterior  cerebral,  which  sends  off— 1st,  the 
anterior  communicans  ;  2nd,  the  arteria  corporis 
callosi ;  and^3PfJ,  the  middle  cerebral,  which  fur- 
nishes the  arteria  choroidear 

p2 


212 


THE   SUBCLAVIAN   ARTERY. 

Extends  as  far  as  the  lower  border  of  the  first  rib. 
It  sends  off  frrc branches. 

A.  Vertebral,  which  ascends  through  the  fora- 
mina in  transverse  processes  of  cervical  vertebra, 
and  gives  off — 1st,  the  arte^b^  modullep  spinaflit 
transv^i^se  ;  2nd,  th^mening^T;  3rd,  the  inferior 
cerebellar ;  4th,  anterior  andj^posterior  gpinal.  The 
basilar  artery,  formed  by  the  union  of  the  two  ver- 
tebrals,  gives  off"  transverse  branches  to  the  pons,  a 
small  branch  which  enters  the  meatus  auditorius 
internus,  and  terminates  by  dividing  into  four  large 
vessels;  the  posterior  cerebral  and  superior  cerebel- 
lar of  each  side. 

B.  Internal  mammary,  which  gives  off — 1st,  the 
comes  ncrvi  phrcnici ;  2nd,  the  mediastinal,  thynttc=' 
and  pericardiac  braiiches  ;  3rd,  the  anterior  inter- 
costals  ;  4th,anteriof'pGrforating  branch(^;5th,  the 
musculo-phrenic  ;  and  0th,  the  superior  epigastric. 

C.  Thyroid  axis,  which  divides  into — 1st,  in- 
ferior thyroid,  which  gives  off  the  cervicafis  as- 
cendens ;  2nd,  supra-scapular,  which  gives  off  a 
supra-acromial  branch,  and  then  passes  into  the 
supra-spinous  fossa  of  the  scapula,  over  the  notch ; 
3rd,  posterior  scapu4*¥r which  gives  oflf' a  superficial 
cervical  branch,  and  then  terminates  in  the  muscles 
of^tb©  scapula.    - 


213 

D.  Superior  intercostal,  supplies  the  two  or 
three  first  intercostal  spaces,  which-  gives  off  the 
cervicalis  profunda  to  anastomose  with  the  princeps 
cervicis  from  the  occipital. 

THE    AXILLARY   ARTERY 

Extends  from  first  rib  to  the  lower  border  of  the 
tendon  of  the  teres  major.     It   sends   off  seven 
branches. 
'       A.  Acromial  thoracic, 

B.  Thoracica  stiprermh  ** 

C.  Thoracica  alaris. 

D.  External  tnammwmjyQ^  long  thoracic. 

E.  Subscapular,  which  sends  off  an  anterior  and 
dorsal  branch. 

E.  Posterior  circumflex, 
G.  Anterior  circumflex, 

THE   BRACHIAL   ARTERY 

Extends  from  the  lower  border  of  the  tendon  of 
the  teres  major  to  a  finger's  breadth  below  the  bend 
of  the  elbow,  and  sends  off  four  branches. 

A.  Profunda  superior,  which  sends  off— 1st,  an 
ascending  branch  ;  and  2nd,  the  musculo-spiral 
branch.     It  accompanies  the  musculo-spiral  nerve. 

B.  Nutritia  humeri, 

C.  Profunda  inferior,  which  accompanies  the 
ulnar  nerve. 

D.  Anastomotica  magna. 


214 


THE   RADIAL  ARTERY 


\ 

Sends  off  tek.branches. 

A.  Recurrent  radial. — It  anastomoses  with  the 
profunda  superior. 

B.  Muscular. 

C.  Superjicialis  voice,  anastomoses  with  the  ulnar 
to  form  the  superficial  palmar  arch. 

D.  Anterior  carpi  radialis,  ^   , 

E.  Dorsal  is  carpi  radiaii^^^^*''^^^  ' 
P.  DorsalA  pollicis,-  X^  '-^^^^  * 
G.  Dorsilis  inditis,  ^f 
H.  Princeps  polUcis. 

I.    Radialis  indicis. 
K.  Palmarls  profuncht: 


THE    ULNAR   ARTERY 

Sends  off  eight  branches. 

A.  Anterior  recurrent,  anastomoses  with  anasto- 
motica  magna. 

B.  Posterior  recwrent,  anastomoses  with  inferior 
profunda. 

C.  Interosseous,  which  sends  off — 1st,  the  comes 
nervi  mediimi ;  2nd,  the  anterior  interosseous  ;  3rd, 
the  posterior  interosseous  ;  4th,  the  posterior  recrriN 
reat.;  and  5th,  the  posterior  descending  branch. 

D.  Muscular. 


215 

E.  Carpi  ulnaris  anterior. 

F.  Carpi  ulnaris  posterior,  a 

G.  Ulnaris  prof  unda; 

II.  Palmar  is  superjicialis,  which  anastomoses 
with  the  supcrficialis  voloe  to  form  the  superficial 
pahnar  arch.  A  long  branch  comes  off  from  the 
ulnar  or  interosseous,  called  the  comes  nervi  rae- 
diani ;  it  is  of  uncertain  size. 

DEEP   PALMAR   ARCH, 

The  deep  palmar  arch  is  formed  by  the  palmaris 
profunda  of  the  radial,  uniting  with  the  arteria 
communicans  from  the  ulnar  ;  it  sends  off  these 
small  branches  interossi,  some  recurrent  branches, 
and  three  perforating  branches. 

THE    SUPERFICIAL   PALMAR   ARCH 

Is  formed  by  the  arteria  palmaris  of  the  ulna, 
uniting  with  the  supcrficialis  volaj  from  the  radial. 
It  sends  off  four  branches. 

A.  Branches  to  ulnar  side  of  little  Jinger. 

B.  Branch  t  cleft  between  little  and  ring  finger. 

C.  Branch  to  clefl  between  ring  and  middle 
fingers.  , 

D.  Branch  to  cleft  between  middle  and  index 
fingers. 


216 


THE    THORACIC   AORTA 


Sends  off  five  sets  of  branches. 

A.  Pericardiac. 

B.  Posterior  mediastinal, 

C.  Bronchial. 

D.  (Esophageal. 

E.  Intercostals,  ten  in  number :  each  divides  into 
— 1st,  the  posterior  branches ;  and  2nd,  the  ante- 
rior branches. 

THE    AORTA   ABDOMINALIS 

Sends  off  the  following  branches  : — 

A.  Tlte  tiuo  phrenic  arteries, 

B.  The  coeliac  axis. — ^From  this  axis  arise — 1  st, 
the  superior  gastric  artery,  which  divides  into  a 
superior  and  an  inferior  branch;  2nd,  the  hepatic 
artery,  which  gives  off  the  superior  pyloric  artery, 
the  gastro-duodenal  artery,  which  divides  into  the 
arteria  pancreatica  duodenalis,  and  the  arteria 
gastro-epiploica  dextra.  The  hepatic  artery  then 
divides  into  the  left  hepatic  and  right  hepatic  arte- 
ries, from  the  last  of  which  proceeds  a  small  branch 
to  the  gall-bladder,  called  arteria  cystica ;  3rd,  the 
splenic  artery,  which  sends  off  the  pancreaticae 
parvas,  the  pancreatica  magna,  the  vasa  brevia, 
splenic  branches,  and  the  gastro-epiploica  sinistra. 


217 

C.  Tlie  superior  mesenteric  artery,  which  gives 
off— 1st,  ths  colica  dextra,  which  divides  into  a 
superior  and  an  inferior  branch;  2nd,  the  colica 
media,  which  divides  into  a  right  and  left  branch ; 
3rd,  the  ilco-colica,  which  divides  into  a  superior 
branch,  a  middle  branch,  and  an  inferior  branch  ; 
4th,  the  mesenteric  branches,  from  fifteen  to  twenty 
in  number ;  and  5th,  the  inferior  pancreatica 
duodenalis. 

D.  Two  capsular,  ' 

E.  Two  renal. 

r.  Two  spermatic. 

G.  Inferior  mesenteric,  which  sends  off — 1st,  the 
colica  sinistra,  which  divides  into  an  ascending 
branch  and  a  descending  branch ;  2nd,  the  sig- 
moid artery ;  and  3rd,  the  superior  hajmorrhoiilal 
artery. 

I.  Lumbar  arteries. 

K.  Sacra  media,  which  gives  off  the  fifth  lumbar 
artery. 

THE    COMMON    ILIAC    ARTERIES 

Extend  from  the  bifurcation  of  the  aorta,  oppo- 
site the  4th  lumbar  vertebra,  and,  after  a  course 
of  about  two  inches,  divide  into  external  and  in- 
ternal near  the  sacro-iliac  symphysis ;  the  right  is 
usually  longer  than  the  left;  they  divide  into  two 
branches — viz.. 


218 


The  internal  J  and 
External  iliac  arteries. 


THE    INTERNAL    ILIAC   ARTEKT 

Sends  off  ten  branches  in  the  female. 

A.  Arteria  ilio-lumhalisy  which  sends  off — 1st, 
ascending  branches ;  2nd,  external  branches ;  and 
3rd,  descending  branches. 

B.  Lateral  sacral,     .^^j;^ —Cti**  tn* 

C.  Vesical,  superior ^iint  inferior, 

D.  Middle  licBmorrlioidcd^ 

E.  Uteiine. 

F.  Vaginal. 

G.  Obturator,  which  sends  off— 1st,  the  branches 
within  the  pelvis  ;  and  2nd,  branches  without  the 
pelvis. 

H.  Gluteal,  which  sends  off — 1st,  a  superficial 
branch;  and  2nd,  a  deep  branch. 

I.  Ischiatic,  which  sends  off— 1st,  the  coccyi^eal 
branch;  2nd,  the  arteria  comes  nervi  ischiatici ; 
and  3rd,  tlie  muscular  branches. 
*fe  Pudic,  which  sends  off— 1st,  the  external 
haimorrhoidal  arteries ;  2nd,  the  superficial  peri- 
neal; 3rd,  the  transversalis  perinei ;  4th,  the  arte- 
ria corporis  bulbosi,  which  gives  a  branch  to 
Cowper's  gland,  and  a  branch  to  the  corpus  spon- 
giosum ;  5th,  the  arteria  corporis  cavernosi  penis; 
and  6th,  arteria  dorsalis  penis. 


219 


THE   EXTERNAL   ILIAC 


Sends  off  two  branches. 

A.  is/) /(/asinc,  which  sends  off — 1st,  the  cremas- 
teric artery  ;  2nd,  the  muscular  artery ;  and  3rd, 
the  pubic  artery. 

B,  Circumjfexa  ilii. 


THE    FEMORAL   ARTERY 

Extends  from  Poupart's  ligament  to  an  opening 
in  the  tendon  of  the  adductor  magnus,  where  it 
becomes  "  popliteal.^'  It  sends  off  the  following 
branches  : — • 

A.  Superficial  epigastric, 

B.  Superficial  pudic, 

C.  Superficial  circumfiexa  ilii. 

D.  Profunda  femoris,  which  sends  off — 1st,  the 
circumfiexa  externa,  from  which  arise  the  ascend- 
ing branches,  the  transverse  branches  and  descend- 
ing branches ;  2nd,  the  circumfiexa  interna,  from 

'  which  arise  arterial  branches  to  the  muscles  of  the 
hip  joint,  and  a  branch  to  the  interior  of  the  hip- 
joint  ;  3rd,  theperforans  prima  ;  4th,  theperforans 
secunda ;  5th,  the  perforans  tertia ;  and  6th,  the 
terminal  branch. 

E.  Anastomotica  magna. 


220 


THE   POPLITEAL   ARTERY 

Lies — -Ist,  upon  posterior  part  of  femur;  2nd, 
upon  the  ligamentum  posticum  Winslowii ;  3rd, 
upon  the  poplitsus  muscle,  and  then  divides  into 
anterior  and  posterior  tibial.  It  sends  off  seven 
branches. 

A.  Superior  muscular. 

B.  Articular'is  superior  externa^  which  sends  off 
a  supei-ficial  branch  and  a  deep  branch. 

C.  Articularis  superior  interna,  which  sends  off 
a  superficial  branch  and  a  deep  branch. 

D.  Azyfjos  branch,  which  perforates  the  ligamen- 
tum  posticum  Winslowii.. 

E.  Articularis  inferior  externa. 
r.  Articularis  inferior  interna, 
G.  Inferior  muscular  or  sural. 

THE    TIBIALIS   POSTICA 

Sends  off — 

A.  Muscular. 

B.  Peronea/,  which  sends  off — 1st,  the  nutritialis 
fibulai;  2nd,  muscular;  3rd,  the  anterior  peroneal; 
and  4tb,  the  posterior  peronerl. 

C.  Nutritialis  tibicE.^  ,  ^-        -jO* 

D.  Internal  plantarTx  % 

E.  External  plantar.  \  ' 


221 


THE    TIBIALIS   ANTICA 

Passes  through  the  interosseous  space,  and  sends 
off  the  following  branches  : — 

A .  Muscular. 

B.  Recurrent  tibial. 

C.  Internal  malleolar, 

D.  External  malleolar. 

E.  Tarsal  branch. 

F.  Metatarsal  branch. 

G.  Arleria  polllciG, 
H.  Arteria  communicans, 

THE    PLANTAR    ARCH 

Is  formed  by  the  external  plantar  artery  uniting 
with  the  arteria  communicans  of  the  anterior 
tibial.    It  sends  off"  two  sets  of  branches  : — 

A.  Arterke  perforantes. 

B.  Arterice  dirjitales. 

THE    PULMONARY    ARTERY 


Divides  into  two  branches  : — 

A.  Right  pulmonary. 

B.  Left  pulmonary. 


222 

VEINS. 

The  veins  are  not  so  uniform  in  their  distribution 
as  the  arteries.  Besides  the  numerous  superficial 
veins  which  ramify  on  the  skin,  one  or  two  are 
found  to  accompany  each  artery.  In  the  extremi- 
ties there  are  generally  two  to  each  artery,  and  in 
these  situations  they  receive  the  name  of  ven^e 
comites.  When,  however,  an  artery  is  of  great 
size,  as  the  femoral  or  the  axillary,  it  is  accom- 
panied but  by  one  vein,  which  receives  the  same 
name  as  the  artery. 

VEINS  ON  THE  HEAD  AND  NECK. 

The  veins  which  accompany  the  branches  of  the 
internal  maxillary  artery  form  the  internal  maxil- 
lary vein. 

External  jugular  vein,  formed  by  the  junction  of 
the  internal  maxillary  and  one  temporal  vein  in 
the  parotid  gland,  descends  obliquely  backwards, 
and  joins  the  subclavian  vein  :  after  crossing  the 
sterno-mastoid  muscle  it  receives  the  supra  and 
posterior  scapular  veins. 

Internal  jugular  vein,  commences  at  the  termi- 
nation of  the  lateral  sinus,  descends  along  the  outer 
side  of  the  common  carotid  artery,  and  joins  the 
subclavian  vein  at  the  sternal  extremity  of  the 
clavicle.  It  receives  the  superior  thyroid,  lingual, 
facial,  occipital,  and  ascending  pharyngeal  veins. 


223 

Anterior  jugular  vein^  descends  in  front  of  neck 
and  opens  into  the  subclavian  vein. 

VEINS  OF  THE  SUPERIOR  EXTREMITY. 

The  Cephalic  vein  is  formed  by  the  union  of 
several  veins  from  the  back  of  the  hand.  It  as- 
cends along  the  radial  side  of  the  extremity,  and 
passing  along  the  interval  between  the  pectoralis 
major  and  deltoid  muscles,  terminates  in  the  axil- 
lary vein. 

The  Basilic  vein  commences  by  a  small  vein 
from  the  little  finger  {vena  salvatclla),  ascends 
along  the  inner  side  of  the  extremity,  and  termi- 
nates in  the  axillary  vein,  or  joins  one  of  the  venoe 
comiles  whicli  accompany  the  brachial  artery. 

The  Median  vein  commences  at  the  fore  part  of 
the  wrist  and  hand,  ascends  along  the  anterior 
aspect  of  the  forearm,  and  at  the  elbow  terminates 
by  dividing  into  two  branches.  One  of  these  joins 
the  basilic  vein,  and  is  named  the  median  basilic ; 
the  other  joins  the  cephalic  vein,  and  is  named 
median  cephalic. 

The  Axillary  vein,  formed  by  the  union  of  the 
veins  just  described,  and  by  the  brachial  vence 
comiteSy  ascends  in  front  of  the  axillary  artery, 
receiving  the  thoracic  veins,  and  passes  b  neath 
the  clavicle,  where  it  terminates  in  the  subclavian 
vein. 

The  Subclavian  vein  passes   inwards   over  the 


224 

anterior  scalenus  muscle,  receives  numerous  veins 
from  the  neck  and  shoulder;  also  the  external 
jugular  and  vertebral  veins,  and  joins  the  internal 
jugular  vein  behind  the  sternal  extremity  of  the 
clavicle. 

Vena  hmominata,  formed  by  the  union  of  the 
internal  jugular  and  subclavian  veins,  on  the  right 
side,  is  very  short,  and  descends  into  the  thorax  ; 
the  left  vena  innominata,  which  is  much  longer, 
enters  the  thorax  in  an  oblique  direction  in  front  of 
the  trachea  to  join  the  right  vein,  and  in  its  course 
receives  the  inferior  thyroid  veins,  and  veins  from 
the  anterior  mediastinum.  By  the  union  of  the 
venae  innominataj  is  formed  the 

Vena  cava  superior,  which  descends  in  front  of 
the  right  pulmonary  vessels,  enters  the  pericardium, 
and  opens  into  the  right  auricle. 

VENA   AZYGOS   MAJOR 

Commences  on  the  first  lumbar  vertebra  by  one 
or  two  small  veins  from  the  renal  or  from  the  infe- 
rior vena  cava,  gains  the  posterior  mediastinum  by 
passing  through  the  aortic  opening  of  the  diaphragm, 
ascends  along  the  right  side  of  the  bodies  of  the 
dorsal  vertebrce,  curves  forwards  over  the  root  of 
the  right  lung,  and  terminates  at  the  posterior 
aspect  of  the  superior  vena  cava,  as  this  vessel  is 
entering  the  pericardium.    In  its  course  it  receives 


225 

the  lower  intercostal  veins  of  the  right  side,  oeso- 
phageal veins,  the  azygos  minor,  right  bronchial, 
and  sometimes  the  right  superior  intercostal  veins. 
It  has  a  few  imperfect  valves. 

Vena  azygos  minor  commences  from  one  of  the 
lumbar  veins,  passes  through  the  aortic  opening 
of  the  diaphragm,  and  after  receiving  the  lower  in- 
tercostal veins  of  the  left  side,  joins  the  vena  azj- 
gos  major  opposite  the  sixth  dorsal  vertebra. 

All  the  veins  of  the  upper  extremity  which 
accompany  the  large  arteries  are  situated  on  a 
plane  anterior  to  their  respective  arteries. 


VEINS   OF   THE    INFERIOR   EXTREMITY. 

Internal  saphena  vein  commences  at  the  inner 
part  of  the  foot,  ascends  along  the  inner  side  of  the 
leg  and  knee,  behind  the  inner  condyle,  becomes 
more  anterior  upon  the  thigh,  and,  reaching  to 
within  about  two  inches  of  Poupart's  ligament, 
passes  through  the  saphenous  opening  of  the  fascia 
lata,  and  joins  the  femoral  vein. 

External  sajihena  vein  commences  at  the  outer 
part  of  the  foot,  ascends  along  the  back  part  of  the 
leg  and  ham,  and  joins  the  popliteal  vein. 

Both  these  veins  are  superficial,  and  in  their 
course  receive  several  veins  from  the  integu- 
ments. 

Deep  veins  of  the  leg,  two  veins  (vcnce  comites) 
Q 


226' 

accompany  each  artery  in  the  leg,  and  terminate  in 
the  following : — 

Popliteal  vein :  this  Yesscl  accompanies  the  ar- 
tery of  the  same  name,  and  having  received  the 
external  saphena  vein,  and  the  veins  of  the  knee, 
terminates  in  the  femoral  vein.  Its  coats  are  very 
thick. 

Femoral  vein  accompanies  the  femoral  artery/ 
and  having  received  the  profunda  vein,  the  internal 
saphena  vein,  and  a  few  muscular  veins,  passes  be- 
neath the  crural  arch,  and  ends  in  the  external 
iliac  vein. 

External  iliac  vein  accompanies  the  external 
iliac  artery. 

Internal  iliac  vein  is  formed  by  the  union  of  the 
veins  which  accompany  the  branches  of  the  inter- 
nal iliac  artery,  and  joins  the  external  iliac  vein 
at  the  sacro-iliac  symphysis. 

Common  iliac  vein,  formed  by  the  union  of  the 
internal  and  external  iliac  veins,  joins  its  fellow  at 
the  right  side  of  the  body  of  the  fourth  lumbar  ver- 
tebra to  form  the  inferior  vena  cava. 

Inferior  vena  cava  ascends  along  the  right  side 
of  the  bodies  of  the  lumbar  vertebrae,  behind  the 
liver,  and  passes  through  the  quadrilateral  opening 
in  the  tendon  of  the  diaphragm,  and  opens  into  the 
right  auricle  of  the  heart  at  its  louver  and  back 
part.  It  receives  the  middle  sacral,  the  right  sper- 
matic vein,  the  renal  and  capsular  veins,  the  venaj 


cavse  hepaticse,  the  phrenic  veins,  and  the  lumbar 
veins. 

The  veins  which  accompany  the  large  arteries  of 
the  lower  extremity  He  posterior  to  their  respective 
arteries,  except  the  renal  and  the  profunda  veins. 

VENA   PORT^ 

Commences  on  the  back  of  the  rectum  by  the 
superior  hcemorrhoidal  vein,  ascends  towards  the 
mesocolon,  and  unites  with  the  splenic  vein,  which 
has  been  previously  joined  by  the  inferior  mesen- 
teric vein,  behind  the  pancreas,  and,  after  receiving 
veins  from  the  stomach,  duodenum  and  pancreas, 
the  common  trunk  joins  with  the  superior  mesen- 
teric veins,  to  form  the  vena  portaj.  The  vena 
portse  ascends  to  the  right  side,  enclosed  in  the 
capsule  of  Glisson,  and  reaches  the  transverse 
fissures  of  the  liver,  where  it  divides  into  two 
branches  :  these  enter  the  liver,  ramify  through  its 
substance  like  an  artery,  and  its  blood  is  returned 
to  the  inferior  vena  cava  by  the  venae  cavse  hepa- 
ticae,  which  are  three  or  four  in  number,  and  open 
into  the  cava  as  this  vessel  is  entering  its  opening 
in  the  diaphragm. 


q3 


228 
THE  DIGESTIVE  APPARATUS. 

THE    MOUTH. 

This  carity  is  bonndcd  superiorly  by  tlie  hard 
and  soft  palate,  inferiorly  by  the  tongue  and  the 
reflections  of  mucous  membrane  from  it  to  the 
j^ums,  and  laterally  by  the  cheeks.  Its  anterior 
opening,  which  forms  the  commencement  of  the 
digestive  canal,  corresponds  to  the  lips;  and  poste- 
riorly it  communicates  with  the  pharynx  through 
the  opening  called  isthmus  faucium,  the  boundaries 
of  which  are  the  soft  palate  and  uvula  superiorly, 
the  tongue  inferiorly,  and  the  pillars  of  the  palate 
and  tonsils  laterally.  Within  the  mouth  we  observe 
the  opening  of  the  three  salivary  glands  and  folli- 
cles, and  the  teeth  of  each  side.  The  parotid  gland 
opens  by  a  single  orifice  opposite  the  second  supe- 
rior molar  tooth  ;  the  submaxillary  gland  of  each 
side,  by  a  single  orifice  at  the  floor  of  the  mouth, 
by  the  side  of  the  reflection  of  mucous  membrane 
called  frsenum  linguae,  and  the  third  salivary  gland 
or  sublingual  by  several  small  orifices  (eight  or  ten) 
on  each  side  of  the  froenum  linguaj.  Is  lined  with 
squamous  epithelium. 

THE   TEETH. 

The  number  of  teeth  in  the  adult  is  thirty-two, 
sixteen  in  each  jaw;  and  to  distinguish  them  from 
the  teeth  of  the  child  they  are  called  permanent. 


229 

They  are  divided  into  eight  incisors,  four  canine, 
eight  bicuspidsj  and  twelve  molars.  The  two  last 
molars  do  not  appear  unlil  late  in  life,  and  hence 
have  been  called  the  wisdom  teeth.  They  are, 
however,  sometimes  wanting. 

In  the  child  the  number  of  teeth  is  only  twenty, 
and  are  called  milk,  deciduous,  or  temporary  teeth. 

They  are  divided  into  eight  incisors,  four  canine, 
and  eight  molars. 

THE    TONGUE 

Is  a  solid  muscular  organ,  occupying  the  floor  of 
the  mouth,  and  is  covered  with  mucous  membrane. 
Posteriorly  it  is  thick,  and  attached  to  the  hyoid 
bone,  anteriorly  it  is  free  and  lies  behind  tlie  teeth. 
The  upper  surface  or  dorsum  is  covered  for  its  front 
half  with  papillae,  circumvallatae,  fungiform  and 
filliform.  The  circumvallate,  seven  to  twelve,  are 
arranged  like  the  letter  V,  the  posterior,  or  one 
forming  the  apex,  lies  in  front  of  the  foramen 
caecum  ;  the  fungiform,  more  numerous,  are  deep 
red,  round  and  blunt ;  the  filliform,  more  numerous 
still,  are  small  tapering  processes  distributed  over 
the  whole  surface  of  the  tongue.  The  muscles 
forming  the  tongue  are  extrinsic  and  intrinsic  ;  the 
former  attach  it  to  other  bones ;  the  latter  are 
placed  within  it,  and  are,  the  superficial  and  in- 
ferior lingualis,  the  transverse  and  vertical  fibres. 


230 

The  nerves  are  the  gustatory,  which  supplies  the 
papillae,  and  anterior  two-thirds  of  the  tongue,  the 
glosso-pharyngeal,  which  supplies  the  base  of  the 
tongue  and  pipillas  circumvallatae,  and  the  hypo- 
glossal which  supplies  the  muscles. 

THE   TONSILS 

Are  placed  uetween  the  anterior  and  posterior 
palatine  arches,  separated  from  the  internal  carotid 
artery  by  the  superior  constrictor.  Their  surface 
is  convex,  and  marked  by  the  orifices  of  about 
fifteen  mucous  crypts ;  their  structure  is  mainly 
lymphoid. 

SALIVARY    GLANDS 

Are  three  in  number — viz.,  the  Parotid,  the  Sub- 
maxillary, and  the  Sub-lingual. 

Parotid  gland,  the  largest  of  the  three,  is  bounded 
superiorly  by  the  zygoma,  posteriorly  by  the  mas- 
toid process  and  sterno-mastoid  muscle,  and  ad- 
vances on  the  side  of  the  face,  partly  resting  upon 
the  masscter  muscle.  It  sends  off  deep  processes, 
which  fill  the  posterior  part  of  the  glenoid  cavity, 
the  fossa  between  the  ear  and  perpendicular  pro- 
cess of  the  lower  jaw,  and  the  intervals  bet\Veen 
the  pterygoid,  digastric,  and  styloid  muscles ;  it 
often  unites  with  the  sub-maxillary  gland.  Its 
duct   {duct  of  Steno)  passes   across  the  masscter 


231 

muscle,  pierces  the  buccinator  muscle,  and  opens 
into  the  mouth  opposite  the  second  superior  molar 
tooth. 

A  prolongation  {sociaparotidis)  Is  iound  between 
Steno's  duct  and  the  zygoma,  the  duct  of  which 
unites  with  that  of  the  parotid  gland. 

In  the  substance  of  the  gland  are  found,  in  the 
following  order,  one  or  more  lymphatic  glands,  the 
pes  anscrinus,  joined  by  branches  from  the  great 
auricular  and  temporal-auricular  nerves,  the  inter- 
nal maxillary  and  temporal  veins  joining  to  form 
the  external  jugular,  and,  lastly,  the  division  of  the 
external  carotid  into  temporal  and  internal  maxillary 
arteries. 

Suh-maxillary  gland,  placed  in  the  digastric 
space,  and  covered  by  the  skin,  platysma  myoldes 
muscle,  and  superficial  fascia,  is  of  oval  figure,  and 
much  smaller  than  the  parotid.  Its  duct  ( Whar- 
tonian)  tr.rns  round  the  posterior  edge  of  the  mylo- 
hyoid muscle,  and  runs  forwards  and  inwards, 
upon  the  hyo-glossus  muscle,  towards  the  frcznum 
UngucB,  at  the  side  of  which  it  opens  into  the 
mouth. 

Sub -Ungual  gland,  placed  between  the  mucous 
membraneof  the  mouth  and  the  mylo-hyoid  muscle, 
is'the  smallest  of  the  salivary  glands  and  opens 
by  several  small  ducts  {Rivinian),  which  perforate 
the  mucous  membrane  reflected  from  the  side  of 
the  tongue. 


232 


THE   PHARYNX 


Is  a  musculo-membranous  bag  of  conical  shape, 
extending  by  its  base  from  tlie  posterior  part  of 
the  mylo-hyoid  ridge  and  base  of  the  skull  to  the 
posterior  aspect  of  the  cricoid  cartilage,  where  it 
terminates  in  the  oesophagus.  It  is  connected  by 
its  posterior  wall  to  the  vertebras  by  loose  cellular 
tissue,  prae-vertebral  fascia,  and  interiorly  it  corre- 
sponds to  the  mouth  and  larynx. 

On  laying  open  the  cavity  of  the  pharynx  by  a 
perpendicular  incision  along  its  posterior  median 
line  the  external  mucous  lining  of  the  bag  will  be 
exposed,  and  the  following  openings  —  viz.^, 
superiorly,  one  on  either  side  of  the  mesial  line, 
the  openings  of  the  posterior  nares ;  more  exter- 
nally, one  on  each  side  the  openings  of  the 
Eustachian  tubes ;  inferior  to  these  is  the  opening 
of  the  mouth  into  the  pharynx,  or  the  isthmus 
faucium;  posterior  and  inferior  to  the  tongue  is 
the  upper  opening  of  the  larynx,  and,  lastly,  the 
opening  of  the  pharynx  into  the  oesophagus. 

THE    (ESOPHAGUS, 

About  nine  inches  in  length,  commences  about 
the  fifth  cervical  vertebra,  and  extends  from  the 
termination  of  the  pharynx  to  the  stomach  ;  above 
it  is  placed  between  the  vertebrae  and  the  trachea, 


233 

inclines  at  the  inferior  part  of  that  tube  to  the  left 
side,  and  passes  behind  its  left  bifurcation  to  reach 
the  posterior  mediastinum.  In  the  mediastinum  it 
descends  forwards,  and  winding  round  the  thoracic 
aorta  passes  through  the  oval  muscular  aperture 
of  the  diaphragm,  to  terminate  in  the  stomach 
opposite  the  9th  dorsal  vertebra.  Its  walls  are 
composed  of  three  layers,  muscular,  areolar,  and 
mucous  ;  its  muscular  coats  consist  of  an  external 
longitudinal  and  an  internal  circular ;  its  upper 
half  is  composed  of  striped,  its  lower  half  of  un- 
striped  muscular  fibres.  The  mucous  membrane  is 
covered  with  squamous  epithelium. 

THE   STOMACH, 

A  large  pyriform  musculo-membranous  bag, 
situated  in  the  epigastric  and  left  and  right 
hypochondriac  regions,  communicating  at  one  ex- 
tremity with  the  oesophagus,  and  at  the  other  with 
the  duodenum. 

Connexions, — Its  large  extremity,  or  fimdus,  to 
the  spleen  by  the  gastro-splenic  omentum;  its 
upper,  concave,  small  edge,  to  the  liver,  by  the 
gastro-hepatic  omentum  ;  and  its  lower,  convex, 
large  edge,  to  the  colon,  by  the  gastro-colic  omen- 
tum. Its  oesophageal  or  cardiac  orifice,  situated 
between  the  fundus  and  lesser  curve,  connects  it  to 
the  diaphragm,  and  its  pyloric  orifice  to   the  duo- 


234 

denum.  The  superior-anterior  surface  of  the 
stomach  looks  towards  the  diaphragm,  ribs,  and 
left  lobe  of  the  liver ;  the  posterior-inferior  surface 
towards  the  meso-colon. 

The  stomach  is  composed  of  three  tunics,  con- 
nected by  cellular  tissue,  an  external  peritoneal 
coat,  an  internal  mucous  coat,  and  between  both 
the  muscular  coat.  The  muscular  fibres  of  the 
stomach  consist  of  three  sets  :  the  longitudinal  are 
seen  along  the  edges  or  curves,  the  oblique  on  the 
fundus,  and  the  circular  are  well  developed  at  the 
centre  of  the  organ,  and  at  its  pyloric  orifice.  The 
mucous  coat,  smooth,  and  of  light  pink  colour,  is 
thrown  into  folds  {rugce),  which  disappear  when 
the  organ  is  distended.  The  mucous  surface 
is  marked  with  innumerable  polygonal  ridges, 
which  enclose  irregular  spaces,  alveoli,  of  about 
-fioth  of  an  inch  in  diameter.  Numerous  round 
dots  are  seen  in  the  spaces  which  are  the  orifices 
of  tubular  gastric  glands.  At  the  cardiac  end 
they  are  tubular,  but  at  the  pyloric  end  they  are 
branched.  Besides  these  there  are  glands  called 
peptic  glands,  situated  in  the  deeper  structure  of 
the  pyloric  end.  At  the  pyloric  oiifice  the  mucous 
membrane  is  thrown  into  a  circular  fold,  which 
forms  an  imperfect  valve  between  the  stomach  and 
duodenum.     It  is  lined  with  columnar  epithelium. 


235 


SMALL  INTESTINES 


Are  divided  into  duodenum,  jejunum,  and  ileum. 

DuodenujUj  the  shortest  portion  of  the  small 
intestines,  forms  a  cur\^e  in  the  concavity  of  which 
is  situated  the  head  of  the  pancreas  ;  it  is  divided 
into  a  superior  transverse  portion,  a  middle  per- 
pendicular portion,  and  an  inferior  transverse 
portion.  The  transverse  portion  mounts  upwards 
and  to  the  right  to  the  under  surface  of  the  liver ; 
the  descending  extends  as  low  as  the  right  side  of 
the  body  of  the  third  lumbar  vertebra ;  the  trans- 
verse portion  crosses  to  the  left  side  of  the  body  of 
the  second  lumbar  vertebra,  and  then  opens  into 
the  jejunum.  The  superior  part  is  covered  by 
peritoneum  on  both  its  surfaces,  and  on  this  ac- 
count is  more  movable  than  the  perpendicular  or 
inferior  portions,  whi9h  are  only  covered  on  their 
anterior  surface  by  this  membrane. 

Besides  the  numerous  mucous  glands  which  open 
on  its  interior  surface,  the  pancreatic  duct  and  the 
common  biliary  duct  enter  at  its  perpcndicul  r 
division,  either  by  a  common  aperture,  or  in  close 
proximity.  This  intestine  differs  not  only  in  these 
particulars  from  the  rest  of  the  small  intestines, 
but  also  in  being  much  larger,  more  dilatable, 
more  fixed  to  its  position,  in  having  a  greater 
number  of  valvulae  conniventes  (or  circular  folds  of 


236 

the  mucous  membrane),  and  in  its  muscular  fibres 
being  much  stronger.  It  also  contains  Brunner's 
glands,  which  are  small  conglomerate  glands  near 
the  pylorus. 

Jejunum  and  Ileum,  form  the  longest  part  of  the 
intestinal  tube,  being  in  general  from  19  to  20  feet 
in  length ;  the  upper  two-fifths  are  given  to  the 
jejunum,  and  the  remainder  to  the  ileum,  but  there 
is  no  definite  limit  between  them,  as  the  intestines 
run  into  each  other  insensibly,  and  from  the  duo- 
denum the  remainder  of  the  small  intestinal  tube 
gradually  diminishes  in  thickness,  has  fewer  val- 
vulai  conniventes,  and  exhibits  less  vascularity  ;  so 
much  so,  that  the  termination  of  the  ileum  is  much 
thinner  and  paler  than  the  upper  part  of  the  jeju- 
num, and  it  is  in  these  situations  only  that  the 
differences  between  both  are  marked  and  striking. 
The  mucous  membrane  of  the  small  intestine  is 
studded  with  glands  of  two  orders — viz.,  the  glan- 
dulce.  soUtarice,  and  the  glandules  agminatce.  The 
solitarise  are  disseminated  like  granules  over  the 
mucous  membrane,  and  the  agminatsc  are  placed 
in  oval  clusters.  Both  these  sets  of  glands  are 
termed  Fever's  glands.  In  the  small  intestines  are 
also  Liebsrkiihn's  glands  and  small  vascular  pro- 
cessus villi.  The  fibres  of  the  muscular  coat  of  the 
small  intestines  take  a  circular  and  longitudinal 
direction,  the  latter  being  placed  externally. 


237 


LARGE    INTESTINE, 

Divided  into  the  c£ccum,  colon,  and  rectum, forms 
about  one-fifth  of  the  intestinal  canal.  It  differs 
from  the  small  intestine  in  its  great  size,  in  being 
sacculated,  in  having  small  processes  along  its  en- 
tire course,  called  appendices  epiploicce,  in  present- 
ing three  well-defined  longitudinal  bands,  in  being 
thinner,  and  in  having  no  valvulae  connivcntes  or 
villi.  It  is  composed  of  an  external  serous  coat, 
an  internal  mucous  coat,  and,  between  both,  a  mus- 
cular coat.  The  fibres  of  the  muscular  coat  are 
longitudinal  and  circular;  the  former  are  collected 
into  three  bands,  which  being  shorter  than  the  in- 
testine throw  it  into  sacculi :  the  latter  resemble 
the  circular  fibres  of  the  small  intestine. 

Ccecum,  or  caput  coli,  placed  in  the  right  iliac 
fossa  and  connected  to  the  iliacus  and  psoas  muscles, 
is  fixed  in  its  situation  by  the  peritoneum,  which 
only  covers  it  anteriorly  and  somewhat  laterally ;  it 
receives  at  its  inner  side  the  ileum,  which  termi- 
nates in  its  cavity  by  a  slit-like  opening,  which  is 
guarded  by  two  valves  ;  these,  in  health,  allow  the 
transit  of  alimentary  and  excremental  matter  from 
the  ileum  to  the  colon,  but  not  in  the  reverse  direc- 
tion. The  inferior  valve  or  ileo-ccecal  is  the  larger, 
and  placed  obliquely ;  the  supeiior  or  ileo-coUc  is 
smaller,  and  rather  horizontal ;  both  are  united  at 


238 

Ihcir  extremities,  forming  the  commissures.  Tlie 
appendix  vermiformis,  is  a  small  diverticulum 
which  proceeds  from  the  posterior  part  of  the 
cjBcum  ;  it  is  the  size  of  a  goose-quill  in  diameter, 
and  from  three  to  five  inches  in  length  ;  its  orifice 
of  entrance  into  the  caecum  is  guarded  by  a  small 
valve ;  the  caecum  has  no  valvule  conniventes,  but 
is  thrown  into  irregular  sacculi  by  the  three  longi- 
tudinal bands  of  muscular  fibres. 

The  colon  extends  from  the  caecum  to  the  rectum, 
and  is  divided  into  four  portions — viz.,  the  right  or 
ascending  colon,  the  middle  or  transverse,  the  left 
or  descending,  and  the  sigmoid  flexure. 

The  rectum  extends  from  the  sigmoid  flexure  of 
the  colon  to  the  anus  ;  its  upper  third  is  wholly 
covered  by  peritoneum,  its  middle  third  is  only 
covered  by  this  membrane  upon  its  anterior  aspect 
and  sidts,  and  its  inferior  third  has  no  peritoneal 
covering.  In  the  male  subject  the  antero-inferior 
aspect  of  the  rectum  is  connected  to  the  inferior 
surface  of  the  bladder,  the  vesiculae  seminales,  and 
the  prostate  gland,  and  in  the  female  to  Ihe  uterus 
and  vagina.  The  rectum  has  the  longitudinal  fibres 
scattered  over  its  whole  surface,  and  is  not  saccu- 
lated like  the  other  parts  of  the  large  intestine 
At  the  anal  orifice  there  are  a  number  of  large 
veins  which  communicate  with  the  superior  haemor- 
rhoidal  vein,  and  thus  indirectly  with  the  portal 
system. 


239 

LIVER, 

Situated  in  the  right  hj'pochondriac,  the  epigas- 
tric, and  partly  in  the  left  hypochondriac  regions, 
is  the  largest  gland  in  the  body,  and  weighs  between 
fifty  and  bixty  ounces.  It  presents  an  upper  convex 
surface,  a  lower  irregularly  concave  surface,  a  pos- 
terior thick  margin  attached  to  the  diaphragm,  and 
an  anterior  inferior  margin  which  is  free.  The 
upper  surface  is  unequally  divided  by  the  falciform 
ligament  into  a  right  and  left  lobe.  The  inferior  sur- 
face presents  the  following  fissures  and  depressions. 

1.  Lougkuduml  fissure,  extends  from  a  notch  in 
the  anterior  thin  edge  of  the  liver  backwards  and 
upwards,  defining  the  boundary  between  the  right 
and  left  lobes  of  the  organ  ;  it  crosses  the  trans- 
verse fissure  at  right  angles,  and  is  continued  to 
the  fissure  of  the  vena  cava  by  a  c^ni\\— fissure 
of  the  ductus  venosus — often  concealed  in  the  sub- 
stance of  the  liver.  As  far  as  the  transverse 
fissure  it  contains  the  remains  of  the  obliterated 
umbilical  vein  ;  beyond  that  point,  the  obliterated 
ductus  venosus. 

2.  Transverse  or  portal  fissure,  extends  from 
the  longitudinal  fissure  into  the  right  lobe  of  the 
liver ;  it  contains  the  trunks  of  the  right  and  left 
hepatic  arteries,  the  trunk  of  the  portal  vein,  the 
hepatic  extremities  of  the  biliary  ducts,  the  hepatic 
plexus  of  nerves  and  absorbents. 


240 

3.  Fissure  of  the  vena  cara,  situated  to  the  right 
of  the  horizontal  fissure  and  behind  the  transverse 
fissure,  forms  the  right  boundary  of  the  lobulus 
Si^igelii. 

4.  Depression  for  the  gall-bladder,  situated  to 
the  right  of  the  lobulus  quadratus. 

5.  A  broad  notch  in  the  posterior  thick  edge  of 
the  liver,  which  corresponds  to  the  right  crus  of  the 
diaphragm. 

Lobes  of  the  liver. — 1st,  right  lobe,  the  largest; 
2nd,  left  lobe,  separated  from  the  right  by  the  lon- 
gitudinal fissure ;  3rd,  lobulus  Spigelii,  bounded  in 
front  bj  the  transverse  fissure,  and  placed  between 
the  ductus  venosus  and  vena  cava ;  4th,  lobulus 
caudatus,  extending  from  the  lobulus  Spigelii  along 
the  right  lobe,  and  lying  posterior  to  the  transverse 
fissure ;  5th,  the  lobulus  quadratus,  which  is  bounded 
behind  by  the  transverse  fissure,  to  the  left  by  the 
horizontal  fissure,  to  the  right  by  the  gall-bladder, 
its  anterior  edge  being  free. 

Vessels  of  the  liver. — 1st,  the  hepatic  artery; 
2nd,  the  vena  portse  ;  3rd,  the  venae  cavge  hepaticaj ; 
4th,  the  biliary  or  hepatic  ducts  ;  and  5th,  the  ab- 
sorbents. The  hepatic  artery  is  the  nutrient  vessel 
of  the  liver  ;  its  terminal  branches  open  into  the 
subdivisions  of  the  vena  portse.  The  vena  porta 
conveys,  like  an  artery,  the  blood  for  secretion  of 
the  liver.  The  biliary  ducts  commence  amongst  the 
lobular  veins. 


241 

Ligaments  of  the  liver. — Besides  the  liver  being 
invested  with  a  thin  capsule,  it  is  also  covered  by 
peritoneum,  which  forms  five  of  its  ligaments — viz., 
1st  and  2nd,  aright  and  left  lateral,  triangular  in 
form,  and  connecting  the  right  and  left  lobes  to 
the  diaphragm ;  3rd,  a  suspensory  or  falciform 
ligament,  which  connects  its  upper  convex  surface 
to  the  right  rectus  muscle,  and  to  the  diaphragm  ; 
4th,  the  coronary  ligament,  which  connects  the 
superior  thick  border  to  the  diaphragm  ;  and  5th, 
the  obliterated  umbilical  vein  [Urjamentum  teres), 
which  extends  obliquely  from  the  umbilicus  upwards 
and  backwards  to  the  anterior  portion  of  the  hori- 
zontal fissure. 

Structure. — The  liver  substance  is  composed  of  a 
multitude  of  polyhedral  lobules,  of  about  half  a  line 
to  a  line  in  diameter.  Between  the  lobules  are 
found  small  branches  of  the  vena  portae,  hepatic 
artery,  and  biliary  ducts,  enclosed  in  a  common 
sheath  derived  from  Glisson's  capsule :  these  veins 
are  called  interlohularj  from  which  are  derived 
numerous  branches,  penetrating  the  lobule  from  its 
circumference  to  its  centre.  The  plexus  thus 
formed  ramifies  between  the  hepatic  cells  in  the 
lobule,  and  is  called  the  lobular  plexus;  the 
branches  of  which  converge  to  the  centre  of  the 
lobule  and  terminate  in  a  single  central  vein,  the 
intralobular  vein.  The  intralobular  vein  opens  into 
the  sublobular  vein,  upon  which  the  lobule  rests, 


242 

and  this  again  terminates  in  an  hepatic  vein  "U'liich 
opens  into  the  vena  cava  inferior.  Tha  hepatic 
artery  runs  along  with  the  branches  of  the  portal 
vein  and  gives  off  vaginal,  capsular  and  interlobu- 
lar, which  supply  the  capsule  and  the  lobules.  The 
interstices  betwsen  the  blood-vessels  are  filled  with 
hepatic  cells ;  and  among  the  cells  may  be  recog- 
nised a  minute  and  close  network  of  channels,  biliary 
capillaries,  which  are  the  commencements  of  the 
bile  ducts.  The  ducts  join  with  other  ducts,  till 
they  collect  into  two  large  ducts,  the  right  and  left 
hepatic. 

Gall-bladder,  pyriformin  shape,  and  composed  of 
an  internal  mucous  coat,  a  proper  fibrous  coat,  and 
a  partial  serous  covering,  is  lodged  in  a  depression 
on  the  under  surface  of  the  right  lobe  of  the  liver. 
Its  large  extremity,  ov  fundus,  is  directed  down- 
wards and  forwards ;  its  upper  extremity  terminates 
in  the  cystic  duct,  about  an  inch  and  a  half  in 
length,  which  unites  with  the  hepatic  duct,  formed 
by  the  union  of  the  right  and  left  ducts  from  the 
corresponding  lobes  of  the  liver.  The  common 
biliary  duct  thus  formed  by  the  cystic  and  hepatic 
ducts  is  called  the  ductus  communis  choledochus, 
which  is  about  five  inches  in  length,  and  conveys 
the  bile  to  the  descending  part  of  the  duodenum. 


243 


PANCREAS, 

A  flattened  elongated  gland  from  five  to  six  inches 
in  length,  similar  in  its  formation  to  the  salivary 
glands.  It  consists  of  a  left  caudal  extremity, 
situated  in  the  lower  part  of  the  left  hypochon- 
drium,  a  body  which  crosses,  anterior  to  the  left 
crus  of  the  diaphragm,  the  aorta  and  the  vena 
portae,  to  the  right  side  ;  and  a  right  extremity 
{the  head),  which  is  the  largest  part  of  the  gland,  and 
which  is  surrounded  by  the  duodenum.  Its  duct, 
of  a  whitish  colour,  extends  along  the  centre  of  the 
gland  from  left  to  right,  but  lying  near  its  anterior 
aspect;  receiving  the  small  ducts  from  the  acini  of 
the  pancreas,  it  finally  opens  into  the  duodenum, 
close  to  the  ductus  communis  choledochus,  which 
it  sometimes  joins. 

THE   SPLEEN 

Is  connected  to  the  large  extremity  of  the  stom- 
ach by  peritoneum  and  blood-vessels,  and  situ- 
ated between  the  stomach  and  the  ribs  of  the  left 
side ;  is  of  deep-blue  venous  colour,  and  varies  in 
weight  from  six  to  fifteen  ounces.  It  is  oval  in 
shape,  convex  on  its  outer,  and  hollowed  out  on  its 
inner  to  form  the  hilus :  and  is  covered  by  fibrous, 
elastic,  and  peritoneal  coats.  The  fibrous — tunica 
propria — covering  sends  down  partitions  {Irabeculce) 
r3 


244 

into  its  substance,  forming  interspaces  in  which 
the  spleen  pulp  is  contained.  The  pulp  is  of 
reddish-brown  colour,  and  consists  of  red  cells  about 
the  size  of  red  blood  cells,  nucleated  cells,  free 
nuclei,  and  caudate  cells.  The  pulp  consists  of 
numerous  branched  connective  tissue  corpuscles, 
which  ultimately  forms  a  still  finer  reticular  tissue. 
The  corpuscles  contain  nuclei,  and  occasionally 
yellow  pigment  granules,  and  blood-cells  in  every 
stage  of  metamorphosis.  Between  the  cells  are 
white  blood-cells  in  larger  quantity  than  in  healthy 
blood. 

The  arteries  of  large  size  divide  on  the  fibrous 
septa,  and  terminate  either  directly  in  the  veins  or 
intermediately  in  lacunar  spaces.  At  the  point  of 
division  of  the  arteries  and  connected  with  their 
sheaths  are  numerous  vesicular  lymphoid  bodies, 
Malpirjhian  corpuscles,  which  contain  whitish  fluid, 
and  which  are  expansions  of  the  lymphoid  tissue, 
which  forms  a  thick  sheath  along  the  blood-vessels. 
It  has  no  excretory  duct. 

THE    SUPRA-RENAL   CAPSULES 

Are  two  flattened,  triangular  bodies  placed  above 
the  kidneys.  On  the  anterior  and  inner  aspect  is 
a  concavity,  the  hilus,  which  transmits  the  supra- 
renal artery.  They  are  over  an  inch  in  length,  and 
weigh  from  one  to  two  drachms.      On  section,  its 


245 

structure  presents  two  parts,  cortical  and  medul- 
lary ;  the  cortical  is  hard,  and  composed  of  fibrous 
stroma  interspersed  with  granular  cells ;  the  me- 
duHary  consists  of  a  thinner  and  more  delicate 
reticular  stroma,  in  which  are  abundant  cells  des- 
titute of  oil  globules. 


URINARY  APPARATUS. 

THE    KIDNEYS, 

Two  glandular  organs  of  oval  form,  situated  be- 
hind the  peritoneum  in  each  lumbar  region,  lying 
upon  the  diaphragm,  psoas  magnus  and  quadratus 
liimborum  muscles,  and  enveloped  in  a  thick  layer 
of  adipose  tissue.  The  right  kidney,  which  is 
rather  lower  than  the  left,  is  below  the  liver,  above 
the  crecum,  and  behind  part  of  the  duodenum,  and 
the  ascending  colon ;  the  left  being  bounded  above 
by  the  spleen,  below  by  the  sigmoid  flexure  of  the 
colon,  and  anteriorly  by  the  descending  colon. 
The  extremities  and  outer  border  of  each  kidney 
are  convex,  whilst  the  inner  margin  presents  a  con- 
cave aspect  called  the  hilus,  which  contains  the 
trunks  of  the  blood-vessels  and  its  excretory  duct, 
entering  in  the  following  order — the  veins  anterior, 
the  arteries  behind  these,  and  the  ureter  obliquely 
behind  both.  Besides  the  adipose  capsule  which 
envelopes  each  kidney,  it  also  has  a  proper  fibrous 


24G 

coat,  which  adheres  loosely  to  its  outer  surface,  and 
sends  prolongations  at  the  hilusinto  its  interior,  as 
far  as  the  calyces.  Each  weighs  from  four  to  six 
ounces.  When  a  section  is  made  through  the  kid- 
ney, its  structure  is  seen  to  consist  of  two  kinds — 
the  cortical  and  the  medullary.  The  latter  con- 
sists of  from  eight  to  sixteen  conical  masses,  the 
pyramids  ofMalpighi,  their  bases  being  directed  to- 
wards the  surface,  and  their  apices,  papillce,  towards 
the  sinus,  which  is  a  continuation  of  the  hilus. 
The  cortical  substance,  placed  externally,  dips 
down  between  the  pyramids,  and  is  of  brownish- 
red  colour,  from  a  line  and  a  half  to  two  lines  in 
thickness.  The  summits  of  the  papillae  are  studded 
with  a  number  of  small  orifices,  which  are  the  ter- 
minations of  the  tuheri  uriniferi.  These  tubes, 
traced  up  through  the  pyramids,  run  a  straight 
course,  branching  dichotomously  at  very  acute 
angles,  and  at  the  bases  of  the  pyramids  continue 
still  a  straight  direction  for  a  short  distance,  pyra- 
viids  of  Ferreiriy  when  they  become  tortuous  and 
convoluted,  and  form  the  cortical  substance. 

The  pelvis  is  the  dilated  funnel-shaped  sac  of 
the  ureter. 

The  infundihula  are  three  funnel-shaped  tubes 
formed  by  the  division  of  the  pelvis. 

The  calyces  are  small  tubes,  formed  by  the  sub- 
dividing of  the  infundibulum,  and  each  embraces 
one  or  two  papilla. 


247 

Papillce  is  the  name  given  to  the  nipple-like 
apices  of  the  pyramidal  fasciculi.  Each  papilla 
presents  numerous  minute  openings,  the  apertures 
of  the  tubes  of  which  the  cones  are  composed ; 
these  apertures  are  not  so  numerous  as  the  tubes, 
several  of  which  are  united  in  one  common  orifice. 

Tuhuli  urinlferi  commence  in  the  cortical  por- 
tion by  round  dilatations ;  they  then  run  a  tortuous 
course,  narrow  somewhat  in  diameter  before  enter- 
ing the  pyramids,  where  they  run  a  straight  course 
as  far  as  the  papilla  :  thence  they  return,  forming 
the  looped  tubes  ofHenle.,  to  the  cortical  substance, 
become  again  tortuous,  and  terminate  in  a  collect- 
ing tube.  These  tubes  unite  to  form  an  excretorij 
tube,  which  ends  at  the  papilla. 

Malpighian  bodies,  xio^^i  ^f  ^^  i^^ch  in  diameter, 
found  only  in  the  cortical  portion,  are  formed  by 
the  dilatation  of  the  uriniferous  tube.  An  afferent 
artery  enters  it  and  breaks  up  into  a  vascular  net- 
work (glomerulus),  terminating  in  an  efferent  vein 
which  emerges  close  to  the  artery,  and  which  forms 
a  secondary  plexus  over  the  tubulus  uriniferus. 
The  aqueous  part  of  the  urine  is  excreted  by  the 
Malpighian  bodies  ;  the  saline  parts  are  separated 
from  the  blood  in  the  venous  capillaries,  which  con- 
vey the  blood  back  to  tlie  renal  vein. 

The  ureters  extend  from  the  termination  of  the 
pelvis  of  either  kidney  to  the  bladder,  Each  ureter, 
about  eighteen  inches  long,  and  of  the  diameter  of  a 


248 

moderate  sized  quill,  passes  behind  the  peritoneum, 
lying  anterior  to  the  psoas  raagnus  muscles  and  to 
the  iliac  vessels,  and  reaching  the  inferior  and  pos- 
terior part  of  the  bladder,  passes  obliquely  between 
its  coats  and  perforates  its  interior  at  the  outer 
angle  of  its  trigone.* 

THE    URINARY    BLADDER. 

This  musculo-membranous  viscus,  when  mode- 
rately distended,  is  of  ovoid  figure,  and  occupies  the 
lower  region  of  the  pelvis,  behind  the  symphysis 
pubis,  and  anterior  and  superior  to  the  rectum  in 
the  male,  and  the  uterus  and  vagina  in  the  female. 

Ligaments  of  the  bladder  are  divided  into  true 
and  false.  The  true  ligaments  are  five  in  number — 
viz.,  two  anterior  and  two  lateral,  and  a  superior. 
The  anterior,  white  and  cord-like,  extend  from  the 
posterior  surface  of  the  pubes  to  the  front  of  the 
prostate  and  neck  of  the  bladder ;  the  latter, 
thinner  and  wider,  are  attached  to  the  sides  of  the 
prostate  and  bladder;  both  are  reflections  of  pelvic 
fascia  :  the  superior  is  formed  by  the  urachus.  The 
false  ligaments  are  five  in  number — viz.,  two  pos- 
terior, two  lateral,  and  one  superior,  and  are  formed 
by  the  reflections  of  the  peritoneum. 

*  To  gain  a  view  of  the  parts  just  described,  a  per- 
pendicular section  of  the  gland  should  be  made  from 
its  convex  to  its  concave  margin. 


249 

The  rerjlons  of  the  bladder  are  divided  into  six- 
1st.  Tke  superior  region^  to  which  are  attached 
the  urachus  and  obliterated  umbilical  arteries.  2nd 
and  3rd.  The  lateral  regions,  on  which  the  vesical 
fascia  of  either  side  passes.  4th.  The  anterior 
region,  the  aspect  of  which  looks  towards  the  recti 
muscles,  the  pubes,  and  the  triangular  ligament  of 
the  urethra.  5th.  TJie  posterior  region,  the  aspect 
of  which  looks  towards  the  rectum  in  the  male, 
and  the  uterus  in  the  female.  Gth.  The  inferior 
region,  or  fundus,  which  rests  on  the  vesiculte 
scminales,  the  prostate  gland,  and  the  rectum  in  the 
male,  and  on  the  uterus  and  vagina  in  the  female. 

Coats  of  the  bladder. — Besides  the  partial  peri- 
toneal covering  which  invests  all  the  posterior 
region  and  the  posterior  parts  of  the  upper  and 
lateral  regions,  there  are  also  three  proper  coats  : 
1st.  Tlie  muscular,  placed  externally,  the  fleshy 
fibres  of  which  take  two  directions ;  the  external 
run  longitudinally;  (the  anterior  and  superior 
fibres  being  stronger,  have  been  distinguished  by 
the  name  of  detrusor  urince:)  deep  fibres  imme- 
diately in  connexion  with  the  mucous  coat,  are 
circular  and  best  developed  around  the  neck  of  the 
bladder.  2nd.  The  cellular  coat ;  and  3rd.  The 
mucous,  which  is  exposed  on  opening  the  bladder. 
This  coat  is  in  general  thrown  into  rugic  by  the 
projection  of  tho  muscular  fibres.  It  is  lined  with 
tcsseluted  cpitheliunL 


250 

The  trigone,  or  vesical  triangle,  is  the  name  given 
to  a  smooth  space  enclosed  between  the  openings  of 
the  ureters  into  the  bladder  and  the  vesical  orifice 
of  the  urethra.  The  mucous  membrane  here  is  very 
closely  connected  with  the  muscular  layer. 

The  uvula  is  a  small  duplicature  of  the  mucous 
membrane  on  the  under  surface  of  the  vesical  orifice 
of  the  urethra,  and  corresponds  to  the  third  lobe  of 
the  prostate  gland. 

The  ujellira,  which  terminates  the  urinary  appa- 
ratus in.  the  male,  being  more  connected  with  the 
reproductive  organs,  we  shall  defer  its  considera- 
tion for  the  present. 

THE    PERITONEUM, 

The  largest  serous  membrane  in  the  body,  lines 
the  parietes  of  the  abdomen,  and  invests  almost  all 
the  abdominal  viscera  ;  like  all  serous  membranes, 
it  is  distinguished  into  two  layers,  a  parietal  and 
a  visceral.  The  abdominal  parietes  being  divided 
by  a  transverse  incision  corresponding  to  the  umbi- 
licus, theuninterrupted  continuity  of  theperitoneum, 
and  the  different  productions  it  forms  in  its  course, 
may  be  thus  demonstrated  : — lining  the  inner  sur- 
face of  the  upper  section  of  the  abdominal  parietes, 
it  ascends  to  the  margin  of  the  thorax, and  lines  the 
inferior  surface  of  the  diaphragm ;  from  this  muscle 
it  is  reflected  on  the  spleen  on  the  left  side,  and  on 


251 

the  liver  on  the  right  side,  forming  its  ligaments 
(vide  ligaments  of  liver).  From  the  transverse 
fissure  of  the  liver,  the  two  layers  which  cover  the 
convex  and  concave  aspects  of  this  gland  meet,  and 
are  conducted  by  the  hepatic  vessels  to  the  lesser 
curvature  of  the  stomrich,  thus  forming  the  gastro- 
hepatic  omentum,  which  contains  the  hepatic  artery, 
portal  vein,  and  biliary  ducts,  surrounded  by  a 
fibrous  structure  called  Glisson's  Capsule.  The 
artery  lies  to  the  left,  the  ductus  communis  chole- 
dochus  to  the  right,  and  the  portal  vein  between 
and  behind.  At  the  lesser  curve  of  the  stomach 
the  two  lamina}  of  the  gastro-hepatic  omentum 
separate  and  enclose  this  organ,  passing  from  its 
left  extremity  to  the  spleen,  thus  forming  the  gastro- 
splenlc  omentum;  at  the  great  curve  of  the  stomach, 
and  lower  extremity  of  the  spleen,  the  two  laminte 
again  meet,  and  descend  in  front  of  the  colon  and  the 
small  intestines  to  the  lower  part  of  the  abdomen  ; 
they  then  turn  upon  themselves  backwards,  and 
ascend,  forming  the  great  omen  turn,  to  the  transverse 
arch  of  thecolon,  where  they  separate  to  enclose  this 
intestine.  Having  enclosed  the  colon,  the  layers 
again  unite  and  form  the  transverse  meso-colon, 
which  passes  backwards  to  the  spine;  having 
arrived  at  the  spine,  the  two  laminae  separate  into 
a  descending  and  an  ascending  layer;  the  descend- 
ing layer  passes  into  the  lumbar  regions,  where  it 
is  reflected  upon  the    ascending  and  descending 


252 

colon,  forming  the  right  and  left  lumbar  meso- 
colon :  ifc  attaches  itself  to  the  left  sides  of  the 
bodies  of  the  lumbar  vertebrae,  forming  the  anterior 
lamina  of  the  root  t)f  the  mesentery  ;  from  thi§ 
fixed  point  it  is  continued  around  the  jejunum  and 
ileum,  forming  the  peritoneal  coat  of  these  intes- 
tines, and  returns  again  to  the  spine,  forming  the 
posterior  lamina  of  the  root  of  the  mesentery.  This 
layer  of  the  transverse  meso-colon,  having  thus 
formed  the  mesentery,  still  pursues  its  descending 
course,  and  passes  into  either  iliac  region,  and  into 
the  pelvis  ;  on  the  right  it  attaches  the  ca?ciim  to 
the  right  iliac  fossa,  thus  forming  the  mcso-caicum ; 
oil  the  kft  side  it  attaches  the  sigmoid  flexure  of 
the  colon  to  the  left  iliac  fossa,  forming  the  sigmoid 
meso-colon ;  and  in  the  middle  it  connects  the 
upper  portion  of  the  rectum  to  the  upper  and  an- 
terior part  of  the  sacrum,  forming  the  mcso-rectum. 
Still  pursuing  its  course  downwards,  and  covering 
the  upper  and  anterior  aspect  of  the  middle  third  of 
the  rectum,  it  is  at  length  reflected  on  the  posterior 
surfiicc  and  sides  of  the  bladder  to  the  superior 
region  of  this  viscus,  from  which,  and  from  the  iliac 
fossa,  it  is  reflected  on  the  inner  surface  of  the 
lower  section  of  the  abdominal  parietes  to  the 
transverse  incision,  from  the  upper  edge  of  which 
the  description  was  commenced.  Having  thus 
traced  the  descending  layer  of  the  transverse  meso- 
colon, the  continuity  of  the  ascending  layer  remains 


253 

to  be  noticed  : — ascending  in  front  of  the  inferior 
and  middle  portions  of  the  duodenum  and  of  the 
pancreas,  it  is  conducted  to  the  diaphragm  by  the 
vena  cava,  where  it  becomes  continuous  with  the 
peritoneum,  which  has  been  reflected  from  the  pos- 
terior aspect  of  the  liver.* 

Foramen  of  Wlnslow. — Bj  this  opening  the 
cavity  which  is  between  the  layers  of  the  great 
ouicntuni  communicates  with  the  general  perito- 
neal cavity  of  the  abdomen.  It  is  of  oval  form, 
being  bounded  anteriorly  by  the  gastro-hepatic 
omentum,  posteriorly  by  the  ascending  layer  of  the 
meso-colon,  superiorly  by  the  liver,  and  inferiorly 
by  the  duodenum. 

Inguinal  pouches. — As  the  peritoneum  is  ascend- 
ing on  the  lower  part  of  the  abdominal  parietes,  it 
is  thrown  in  to  four  pouches,  two  on  either  side,  by 
the  obliterated  hypogastric  artery.  The  external 
pouch,  between  the  ilium  and  hypogastric  artery, 
is   the  largest,  and   corresponds   to   the  internal 

*  This,  the  nsnal  description  of  the  perlfconenm, 
leaves  unexplained  the  way  in  which  the  hepatic  vessels 
reach  the  liver  without  perforating  the  membrane. 
This  point  can  be  understood  only  by  referring  to  the 
history  of  the  development  of  the  foetus,  in  which  the 
intestinal  tube,  nearly  vertical,  is  bound  to  the  spinal 
column  by  two  folds  of  peritoneum,  between  which  lie 
the  aorta  and  its  branches.  When  the  viscera  assume 
the  position  known  in  the  adult,  it  is  impossible  to 
trace  all  the  peritoneal  folds. 


254 

abdominal    and  the   femoral  rings;    the   internal 
corresponding  to  the  external  ring. 

In  the  female  the  peritoneum  passes  from  the 
rectum  on  the  upper  and  back  part  of  the  vagina, 
from  which  it  ascends  on  the  uterus,  forming  on 
each  side  its  broad  ligaments,  and  is  reflected  from 
the  anterior  part  of  the  uterus  to  the  back  of  the 
bladder. 


MALE  ORGANS  OF  GENERATION. 

THE    COVERING    OF   THE    TESTES. 

The  scrotum^  a  pouch  of  the  common  integu- 
ment, is  of  reddish-brown  colour,  slightl}'  studded 
with  hairs  and  sebaceous  follicles,  presenting  in  the 
median  line  a  ridge,  called  the  raphe,  on  each  side 
of  which  it  is  thrown  into  rugae. 

The  dartos,  composed  of  areolar  tissue  mixed 
with  unstriped  muscular  fibres. 

The  spermatic  fascia  is  mixed  with  the  dartos, 
and  is  derived  from  the  pillars  of  the  external  ab- 
dominal ring. 

The  cremasteric  fascia  is  a  thin  muscular  cover- 
ing derived  from  the  cremaster  muscle. 

The  infundihuliform  fascia^  derived  from  the 
fascia  transversalis  during  the  descent  of  the 
testes. 


255 

Septum  scroti. — This  partition,  which  divides 
the  scrotum  into  two,  is  formed  by  the  dartos  and 
superficial  fascia,  these  membranes  being  attached 
to  the  raphe,  and  from  thence  ascending  between 
the  testes  to  the  penis, 

PROPER  COATS  OF  EACH  TESTIS. 

Tunica  vaginalis. — A  serous  membrane,  one 
layer  covering  the  testis,  called  tunica  vaginalis 
testis,  the  other  lining  the  scrotum,  called  tunica 
vaginalis  scroti.  When  the  tunica  vaginalis  scroti 
is  cut  open,  its  continuity  with  the  visceral  layer 
may  be  demonstrated  by  tracing  the  membrane, 
when  it  is  seen  to  be  reflected  on  the  side  and 
front  part  of  the  cpididymus  and  testis,  forming  a 
pouch  between  these  bodies  and  also  for  a  short 
distance  on  the  front  aspect  of  the  cord. 

Tunica  albuginea,  a  strong  fibrous  investment 
of  opaque  white  colour,  which  forms  the  proper 
capsule  of  the  gland.  From  its  inner  aspect  there 
is  reflected  into  the  back  part  of  the  testis  an  im- 
perfect sep.tum  called*  the.  corpus  Ilighmorianum: 
from  the  free  edge  of  this  proceed  fibrous  bands, 
trabeculce,  forming  interspaces  which  contain  the 
conical  bundles  of  the  tubuli  seminiferi. 

Tunica  vasculosa,  a  vascular  layer  beneath  the 
tunica  albuginea,  and  sends  in  branches  to  supply 
the  testis. 


.25G 


THE    TESTICLES 

Are  two  in  number,  of  oval  form,  are  contained 
in  the  scrotum,  and  are  also  enveloped  by  the 
tunics  already  described.  The  interior  of  the 
gland  is  divided  into  a  number  (250)  of  small  lobes 
of  pyramidal  form,  their  apices  being  towards  the 
corpus  Highmorianum.  Each  lobe  is  composed  of 
two  or  three  convoluted  tubes,  tubuli  seminiferi, 
which  average  in  length  about  two  feet  and  a  half. 

Tiihuli  seminiferi  are  numerous  small  yellow 
tubes,  which  form  the  body  of  each  testicle.  They 
are  very  long  and  tortuous,  and  arranged  in  conical 
fasciculi,  which  arc  separated  from  each  other  by 
fibrous  bands,  derived  from  the  tunica  albuginea. 

Vasa  recta,  from  twenty  to  thirty  in  number,  are 
formed  by  the  union  of  the  tubuli  seminiferi,  and 
are  contained  betweeen  the  layers  of  the  corpus 
Highmorianum  :  these  form  the  reie  testis. 

Vasa  efferentia,  twelve  to  fifteen  in  number,  are 
formed  by  the  union  of  the  vasa  recta.  These 
tortuous  vessels  pierce  the  tunica  albuginea,  arrive 
at  the  head  of  the  cpididymus,  and  by  their  union 
form  the  vas  deferens.  They  are  here  called  "  coni 
vasculosi." 

Vas  deferens,  or  seminal  excretory  duct,  is 
eighteen  inches  in  length,  and  is  folded  on  itself  by 
innumerable  turns  for  the  first  part  of  its  course. 


By  its  convolutions  it  forms,  with  the  vasa  cfTc- 
rentia,  the  globus  major,  or  head  of  the  epididymis, 
which  is  situated  at  the  upper  part  of  the  body  of 
the  testicle  ;  still  convoluted,  it  passes  downwards, 
forming  the  body  of  the  epididymis,  which  is 
narrow,  and  placed  at  the  posterior  part  of  the 
body  of  the  testicle,  and  arriving  at  the  inferior 
part  of  the  gland  it  forms  the  globus  minor,  or  tail 
of  the  epididymis.  The  vas  deferens,  having  thus 
formed  the  epididymis,  escapes  from  the  globus 
minor,  and  having  increased  in  size  and  density, 
ascends  along  the  inner  aspect  of  this  body,  until 
it  becomes  connected  to  the  spermatic  vessels  and 
cremaster  muscle  ;  it  then  passes  through  the  ex- 
ternal abdominal  ring  and  the  inguinal  canal,  and 
having  passed  through  the  internal  abdominal 
ring,  it  separates  from  the  spermatic  vessels,  and  is 
conducted  by  the  false  lateral  ligament  of  the 
bladder  to  this  viscus,  along  the  side  and  inferior 
part  of  which  it  runs,  lying  internal  to  its  corre- 
sponding vesicular  scminalis.  It  here  approaches 
its  fellow  of  the  opposite  side,  and  both  ducts,  be- 
coming flattened,  arrive  at  the  base  of  the  pros- 
tate gland,  where  they  are  joined  by  the  ducts  of 
the  vesiculae  seminales,  their  union  forming  the 
common  ejaculatory  ducts;  these  run  through  the 
prostate  gland,  and  open  into  the  prostatic  portion 
of  the  urethra,  at  the  side  of  the  verumontanum. 
Each  testicle  is  supplied  with  blood  by  the  sper- 
S 


258 

matic  artery,  the  blood  of  which  is  returned  bv  the 
spermatic  veins ;  it  receives  nerves  from  the  sper- 
matic plexus,  which  is  formed  by  branches  from 
the  renal  and  aortic  plexuses  of  the  sympathetic. 

Rete  testis. — Upon  separating  the  laminae  of  the 
tunica  albuginea,  which  form  the  corpus  High- 
morianum,  the  vasa  recta  will  be  seen  to  pass  to 
and  from  the  gland.  The  reticular  appearance 
these  present  is  called  rete  testis. 

Vas  aherrans  is  a  small  closed  tube,  from  two 
inches  to  twelve  inches,  which  is  connected  with 
the  commencement  of  the  vas  deferens,  running  up 
amongst  the  vessels  of  the  cord. 

Organ  of  Giraldes  is  placed  in  front  of  the  cord 
just  above  the  globus  major,  and  consists  of  several 
masses  of  convoluted  tubes  :  is  sometimes  called 
parepididi/m  is. 

The  spermatic  cord  is  composed  of  the  vas 
deferens,  with  its  small  artery,  derived  from  the 
superior  vesical ;  the  spermatic  artery,  veins,  and 
nerves  ;  the  genito-crural  nerve,  an  artery  to  the 
cremaster  coming  off'  from  the  epigastric,  and  ab- 
sorbents ;  all  of  which  are  connected  to  each  other 
by  fine  cellular  tissue,  and  are  enveloped  by  fascia 
and  the  cremaster  muscle.  The  cord,  thus  formed, 
extends  from  the  epididymus  to  the  internal  abdo- 
minal ring,  where  its  constituents  separate  from 
each  other. 

Plesnx  pampiniformis  is  the  name  given  to  the 


259 

venous  plexus  formed  by  the  spermatic  veins  after 
these  vessels  have  emerged  from  the  testicles. 

The  vesiculce  seminales  are  two  oblong  flattened 
bodies,  situated  at  the  inferior  fundus  of  the  bladder, 
behind  the  prostate  gland,  and  on  the  outer  side  of 
the  vasa  deferentia.  Each  seminal  vesicle  is  about 
two  inches  long,  and  consists  of  a  long  tortuous 
membranous  tube,  convoluted  on  itself,  the  small 
excretory  duct  of  which  joins  its  corresponding  vas 
deferens. 

The  prostate  gland  is  a  flat  conoidal  body,  the 
base  being  posterior,  corresponding  to  the  vesiculse 
seminales,  the  apex  anterior,  corresponding  to  the 
vesical  extremity  of  the  urethra.  It  is  divided  into 
three  lobes ;  two  lateral,  large,  and  united  in  the 
mesial  line,  their  union  being  marked  by  a  slight 
groove  ;  and  a  third  or  small  lobe,  situated  in  the 
angle  between  the  two  lateral  lobes,  towards  the 
base  of  the  gland.  The  prostate  gland  is  firm  and 
resisting  to  the  touch,  and  composed  of  numerous 
follicles,  with  minute  ducts  and  muscular  tissue  ; 
the  ducts  unite  to  form  larger  tubes,  the  openings 
of  which,  ten  or  twelve  in  number,  are  on  the  under 
surface  of  the  urethra,  on  either  side  of  the  veru- 
montanum. 

Coivper's    glands   are  two  small   oblong  round 
bodies,  placed  before  the  prostate  gland,  and  im- 
mediately behind  the  bulb.     They  lie  between  the 
layers  of  the  triangular  ligament.     The  duct  of 
s  2 


260 

each  gland,  having  run  a  course  of  about  an  inch, 
opens  into  the  urethra  a  little  anterior  to  its  bulb. 

THE    PENIS. 

This  organ  consists  of  two  long  cylindrical 
bodies,  named  corpora  cavernosa,  and  a  body 
named  corpus  spongiosum,  which  contains  the 
urethra,  all  these  parts  being  connected  together 
and  surrounded  by  the  superficial  fascia  and  the 
common  integuments. 

The  superficial  fascia,  which  envelopes  the 
penis,  is  derived  from  that  of  the  abdomen,  and 
terminates  at  the  corona  glandis.  It  is  strong 
where  it  passes  from  the  linea  alba  upon  the  dorsum 
of  the  penis,  forming  the  suspensory  ligament,  but 
is  exceedingly  delicate  and  loose  upon  the  body  of 
the  organ. 

The  sJcin  of  the  penis  is  remarkably  thin  and 
loose,  and  extending  for  an  indefinite  length  be- 
yond the  organ,  is  reflected  inwards,  and  intimately 
attached  to  the  corona  glandis ;  the  loose  fold  thus 
formed  being  called  the  prepuce.  From  the  corona 
glandis  it  is  continued  along  the  glans  until  it 
becomes  identified  with  the  mucous  membrane  at 
the  orifice  of  the  urethra,  having  first  formed  the 
fold  which  lies  posterior  and  inferior  to  this  open- 
ing, called  frcenum  preputii. 

Glandulce  odorifercB^  are  a  number  of  small  seba- 


2G1 

ccoiis  glands  wliich  surround  the  corona  glandis, 
and  wliich  lie  beneath  the  skin. 

The  corpora  cavernosa  are  two  cylindrical  bodies, 
united  to  each  other  for  their  anterior  three-fourths 
in  the  mesial  line.  They  are  composed  of  erectile 
tissue,  vessels,  and  nerves,  surrounded  by  a  dense 
fibrous  covering. 

Each  corpus  cavernosinn  commences  by  the 
crus  penis,  which  is  the  narrowest  part,  and  which 
is  attached  to  the  rami  of  the  ischium  and  pubes, 
covered  by  the  erector  penis  muscle.  At  the  sym- 
physis pubis  both  crura  unite,  forming  the  chief 
part  of  the  body  of  the  penis,  and  terminate  ante- 
riorly in  an  obtuse  point,  to  which  is  intimately 
attached  the  glans  penis. 

Septum  pecthnforme,  a  partition,  imperfect,  as 
its  name  implies,  which  corresponds  to  the  mesial 
line,  and  marks  the  division  of  the  corpora  caver- 
nosa. 

The  corpus  spongiosum  urethrce  is  a  cellulo- 
vascular  tube  surrounding  the  urethra,  and  occupy- 
ing the  under  mesial  line  of  union  of  the  corpora 
cavernosa ;  it  commences  in  the  bulb  of  the  urethra, 
and  extends  along  the  canal  to  its  extremity,  where 
it  terminates  in  the  glans  penis,  the  bulb  and  glans 
penis  being  merely  expansions  of  this  structure. 

Structure  of  the  corpus  cavernosum.  From  the 
fibrous  covering  numerous  prolongations,  iraheculce, 
pass  inwards,  intersecting  each  other  in  all  direc- 


262 

tions,  dividing  it  into  innumerable  spaces,  which 
give  a  spongy  appearance  to  its  structure.  The 
trabecular  tissue  contains  some  unstriped  muscular 
tissue,  and  the  venous  interspaces  are  lined  with 
flattened  epithelium  cells.  The  arteries  are  sup- 
l^orted  by  the  trabeculse,  which,  after  very  minute 
subdivision,  open  some  into  the  trabecular  spaces, 
and  others  terminate  in  curled  dilated  extremities 
called  helicine  arteries.  The  structure  of  the  cor- 
pus spongiosum  resembles  the  former,  with  the  ex- 
ception that  the  fibrous  and  trabecular  tissue  is 
much  less  developed. 

The  urethra  is  a  membranous  canal,  extending 
from  the  neck  of  the  bladder  to  the  extremity  of 
the  glans  penis,  its  length  varying  according  to  the 
erect  or  lax  state  of  the  organ. 

In  the  latter  condition  it  is  from  seven  to  eight 
inches  long,  and  its  calibre  about  three  or  four 
lines.  It  is  lined  by  mucous  membrane,  and  is 
distinguished  into — 1st,  the  prostatic  portion,  which 
is  an  inch  and  a  quarter  in  length ;  2nd,  the  mem- 
branous portion,  which  is  about  three-quarters  of 
an  inch  long ;  3rd,  the  bulbous  portion,  which  is 
scarcely  an  inch ;  and  4th,  the  spongy  portion, 
which  occupies  the  remainder  of  its  length. 

Upon  exposing  the  mucous  surface  of  the  urethra 
by  fin  incision,  we  observe — 1st,  a  slit-like  contrac- 
tion at  the  orifice ;  2nd,  behind  this  is  a  dilatation, 
called  fossa  navicular  is ;  3rd,   the  constant   dia- 


263 

meter  of  the  canal  until  we  arrive  at  the  bulb, 
where  it  becomes  gradually  and  very  slightly  di- 
lated ;  forming,  4th,  the  sinus  of  the  bulb ;  5th, 
the  narrowest  part  of  the  canal,  which  corresponds 
to  the  membranous  portion  ;  6th,  the  dilatation  cor- 
responding to  prostate  gland ;  and  7  th,  a  contracted 
orilice  at  its  termination  in  the  bladder.  In  the 
prostatic  portion  of  the  urethra,  a  prominent  fold  of 
mucous  membrane,  called  verumontanum,  projects 
from  its  under  surface,  and  presents  in  its  centre  a 
large  lacuna,  the  sirius  pocularis,  the  orifice  of 
which  is  directed  forwards.  On  either  side  of  the 
verumontanum  the  prostatic  sinuses  are  situated. 
Upon  the  upper  surface  of  the  urethra,  from  the 
orifice  to  the  bulb,  are  the  openings  of  numerous 
mucous  follicles,  directed  forwards,  the  largest  of 
which  is  about  an  inch  from  the  orifice,  and  is 
called,  from  its  size,  lacuna  magna.  The  ducts  of 
the  seminal  glands,  already  described  in  connexion 
with  the  genito-urinary  organs,  open  on  the  under 
surface  of  the  urethra;  the  orifices  of  Cowper's 
glands  open  a  little  anterior  to  the  sinus  of  the 
bulb,  the  common  cjaculatory  ducts  on  either  side 
of  the  verumontanum,  and  the  ducts  of  the  prostate 
in  the  prostatic  sinuses. 


264 


THE  FEMALE  ORGAXS  OF  GENERATION. 

The  mons  veneris  is  a  soft  adii^ose  eminence, 
situate  on  the  upper  and  anterior  part  of  the  pubes, 
covered  by  common  integument,  which  after  puberty 
is  thickly  set  with  hairs. 

The  vulva  is  the  fissure  extending  from  the  mons 
veneris  downwards  and  backwards. 

The  labia  magna  are  large  folds  of  the  integu- 
ments which  bound  the  vulva  on  each  side,  and 
unite  below  in  a  crescentic  edge  [the  fourchette). 
They  contain  large  mucous  glands  about  the  centre. 

77ie  clitoris,  a  small  oblong  conical  body,  placed 
between  the  upper  extremities  of  the  labia.  It  con- 
sists of  a  structure  similar  to  the  corpus  caver- 
nosum  in  the  male,  and  arises  by  two  crura  from 
the  pubes ;  these  unite  to  form  its  body,  at  the  ex- 
tremity of  which  is  placed  a  red  protuberance, 
called  the  glans  ditoridis,  over  which  is  thrown  a 
loose  fold  of  integument  [the  prepuce). 

Meatus  urinarius  is  about  half  an  inch  below 
the  clitoris,  and  three-quarters  of  an  inch  long,  and 
is  placed  at  the  bottom  of  a  depression  called  the 
vestibule. 

Labia  parva,  or  nymphoe,  are  two  red  crescentic 
folds  of  mucous  membrane,  enclosing  numerous 
erectile  vessels  ;  they  descend,  one   on  each  side, 


2G5 

from  the  prepuce  of  the  clitoris,  and  are  lost  about 
the  centre  of  the  vulva. 

The  hymen,  when  it  exists,  is  a  crescentic  fold 
of  mucous  membrane,  surrounding  the  sides  and 
inferior  orifice  of  the  vagina. 

Tlie  caruncukie  myrtiformes  are  small  reddish 
bodies  surrounding  tha  orifice  of  the  vagina  :  they 
are  sometimes  described  as  the  remains  of  the 
hymen. 

The  ovaries  are  two  ovoidal  bodies,  placed,  one 
on  each  side  of  the  uterus,  in  the  duplicatures  of 
the  peritoneum,  called  the  broad  ligaments.  Each 
ovary,  enveloped  by  a  white  fibrous  membrane, 
consists  of  a  pulpy  brownish-grey  substance,  highly 
vascular,  and  containing  from  fifteen  to  twenty 
minute  vesicles,  each  of  which  is  composed  of  a  thin 
membrane  containing  a  viscid  yellowish  fluid;  these 
are  called  the  Graajian  vesicles,  in  which  are  con- 
tained the  germinal  vesicles  or  ovum. 

The  Fallopian  tubes  are  the  ducts  of  the  ovaries; 
each  is  about  four  inches  in  length,  and  is  con- 
tained in  the  broad  ligament,  one  extremity  being 
attached  to  the  superior  angle  of  the  uterus,  into 
which  it  opens  by  a  small  orifice,  the  other  being 
free,  and  terminating  in  a  fringe  {corpus  Jz/nbri- 
atum),  in  the  centre  of  which  is  the  peritoneal 
aperture. 

The  uterus  is  a  hollow  organ  of  pyriform  shape, 
and  is  distinguished  into  the  fundus,  the  boclij,  and 


2Go 

cervix.  The  fundus  is  superior  and  posterior,  and 
receives  at  either  angle  the  Fallopian  tube :  the 
body  is  intermediate  between  the  fundus  and  the 
neck,  the  latter  being  inferior  and  anterior,  and 
surrounded  by  the  vagina  :  at  the  extremity  of  the 
neck  is  a  small  elliptical  opening,  surrounded  by  a 
thick  margin,  which,  from  its  resemblance  to  the 
mouth  of  a  tench,  has  been  called  os  tincce,  as  well 
as  OS  uteri.  The  cavity  of  the  uterus  is  small,  com- 
pared to  the  thickness  of  its  walls,  and  is  of  trian- 
gular shape  ;  its  superior  and  outer  angles  present- 
ing the  orifices  of  the  Fallopian  tubes,  the  inferior 
angle  presenting  the  os  tincse.  The  uterus  is  placed 
between  the  bladder  and  rectum. 

The  vagina  is  a  membrano-vascular  tube,  extend- 
ing from  the  neck  of  the  uterus  to  the  external 
outlet,  where  it  is  continuous  with  the  surface.  It 
is  composed  of  a  reflection  of  integument,  resem- 
bling mucous  membrane,  surrounded  by  cellular 
tissue,  a  vascular  network,  and  the  sphincter  va- 
ginae muscle ;  its  length  is  about  four  inches,  its 
breadth  one;  but,  being  very  distensible,  these 
measurements  vary.  Its  lining  membrane  is  thrown 
into  transverse  rugae  on  its  anterior  and  posterior 
surface,  and  is  studded  with  the  orifices  of  numer- 
ous mucous  follicles.  The  color  of  the  membrane 
varies,  at  the  external  orifice  being  red,  and  of  a 
grey  and  sometimes  marbled  colour  as  it  approaches 
the  uterus. 


267 


THE    MAMM^ 

Are  two  in  number,  and  situated  at  the  anterior 
and  superior  part  of  the  thorax,  and  connected  to 
the  great  pectoral  muscle  by  a  capsule  of  condensed 
cellular  tissue.  Each  of  these  glands,  of  a  hemi- 
spherical shape,  consists  of  vessels  and  numerous 
lactiferous  tubes,  arising  from  sacculated  blind  ex- 
tremities :  the  tubes  are  grouped  together  to  form 
lobes  and  lobules ;  as  they  approach  the  nipple  they 
become  considerably  dilated,  and  form  sinuses,  but 
in  the  nipple  they  are  again  reduced  in  size,  and 
terminate  at  the  apex  by  open  orifices,  surrounded 
by  delicate  elastic  tissue.  The  nipple  is  a  conical 
process  surrounded  by  a  brownish  areola,  and 
composed  externally  of  the  integuments,  which  are 
very  thin,  and  internally  of  the  lactiferous  tubes, 
togetherwith  numerous  blood-vessels  and  muscular 
tissue,  from  which  the  nipple  derives  its  property 
of  erection. 


ORGANS  OF  THE  SENSES. 

THE    ORGAN   OF   TOUCH. 

The  slcin  is  composed  of  the  cuticle  or  epidermis, 
the  rete  mucosum,  and  the  corium,  or  cutis  vera. 
The  cuticle  consists  of  strata  of  epithelium  cells  : 


268 

the  deeper  are  elongated  and  perpendicular,  the 
supei-iicial  are  flattened  and  dried ;  they  are  depo- 
sited in  thickest  layers  upon  the  soles  and  palms. 

The  rete  mucosum,  or  Malpigliian  la^er,  is  the 
softer  and  deeper  part  of  the  cuticle,  and  in  it  are 
found  pigment  granules,  upon  which  depend  the 
black  colour  of  the  skin  in  the  negro. 

The  corium  is  a  thick,  vascular,  sensitiA'e  tissue, 
from  half  a  line  to  a  line  and  a  half  in  thickness. 
Below  it  is  connected  with  the  deeper  structures  by 
subcutaneous  cellular  tissue  and  fat,  and  super- 
ficially with  the  cuticle.  It  consists  of  connective 
tissue  fibres  interlacing  each  other,  which  are  finer 
and  firmer  the  nearer  they  are  to  the  surface. 
Unstriped  muscular  fibres  are  intimately  mixed 
with  it  wherever  hairs  are  found.  The  superficial 
part  of  the  corium  is  called  the  papillary,  the 
deeper  part  the  reticular  layer ;  the  latter  contains 
sudoriparous  and  sebaceous  glands,  hairs,  and  fat ; 
the  former,  the  papillse  and  terminations  of  vessels 
and  nerves.  The  papilla  are  conical  eminences 
composed  of  corium,  from-i-^  to  j^jjo  of  an  inch  in 
height,  and  are  usually  arranged  in  curved  lines, 
sometimes  double.  They  are  furnished  with 
nerves,  which  terminate  at  the  top  in  plexuses  or  in 
tactile  corpuscles :  besides  these,  a  very  delicate 
network  of  blood-vessels  and  lymphatics  pass  to  the 
extremity  of  the  papilla. 


2G9 


THE    ORGAN   OF    SMELL. 


The  nose  is  bounded  superiorly  by  the  nasal, 
frontal,  ethmoid,  and  sphenoid  bones  ;  infcriorly  by 
the  palatine  plates  of  the  superior  maxillary  and 
palate  bones;  externally  on  either  side  by  the  supe- 
rior maxillary,  lachrymal,  inferior  spongy,  ethmoid, 
and  palate  bones,  and  by  the  internal  pterygoid 
plates  of  the  sphenoid  bone.  It  is  divided  into  the 
tivo  nares  by  the  septum  nasi,  which  is  formed  by 
the  rostrum  of  the  sphenoid  bone,  the  nasal  plate 
of  the  ethmoid  bone,  the  vomer,  the  mesial  crests  of 
the  superior  maxillary  and  palate  bones,  the  crest 
formed  by  the  two  nasal  bones,  and  the  nasal  spine 
of  the  frontal  bone.  Besides  the  bony  boundaries 
the  nose  presents,  anteriorly,  five  cartilages,  which 
form  the  anterior  nares,  or  the  nostrils.  The 
middle  vertical  cartilage  is  of  triangular  form,  and 
rests  in  the  fissure  of  the  vomer  infcriorly,  is 
attached  to  the  vertical  plate  of  the  ethmoid  bone 
above,  and  presents  anteriorly  a  subcutaneous,  free, 
thick  edge,  and  thus  completes  the  septum  nasi. 
The  lateral  cartilages  which  form  the  wings  of  the 
nose  are  also  triangular,  are  attached  to  the  superior 
maxdlary  and  nasal  bones,  and  in  the  median  line  to 
.  the  vertical  cartilage.  The  inferior  lateral  fibro 
cartilages  are  attached  to  the  three  cartilages  just 
described,  are  thick  and  semicircular,  forming,  with 


270 

the    vertical   cartilage,  the   anterior-inferior  oval 
openings  of  the  nostrils. 

The  posterior  nares  are  of  oval  shape,  and  open 
into  the  upper  part  of  the  pharynx ;  they  are  sepa- 
rated from  each  other  by  the  posterior  free  edge  of 
the  vomer,  are  bounded  superiorly  by  the  body  of 
the  sphenoid  bone,  inferiorly  by  the  palate  bones, 
and  externally  by  the  internal  pterygoid  plates  of 
the  sphenoid  bone.  The  external  lateral  wall  of 
each  nostril,  from  the  arrangement  of  the  spongy 
bones,  forms  three  fossae,  called  mealuses,  wiith 
which  several  orifices  communicate. 

In  the  inferior  meatus,  at  the  junction  of  its  an- 
'  terior  with  its  middle  third,  is  the  opening  of  the 
nasal  duct,  and  posteriorly,  on  a  level  with  the  in- 
ferior spongy  bone,  is  the  opening  of  the  Eustachian 
tube.  In  the  viiddle  meatus  is  the  slit-like  opening 
of  the  antrum  maxillare,  anterior  to  which  is  the 
groove  called  infandihulum,  which  leads  from  the 
frontal  sinus,  and  into  which  open  the  anterior 
ethmoidal  cells. 

Into  the  superior  meatus  the  posterior  ethmoidal 
cells  and  the  sphenoidal  sinus  open.  The  interior 
of  the  nose  is  lined  with  the  Schneiderian  mem- 
brane, which  is  highly  vascular  and  sensitive,  and 
consists  of  two  layers;  a  fibrous  layer,  which  is  the 
periosteum,  or  the  perichondrium  of  the  nasal  cav- 
ities, and  a  mucous  membrane.  The  nerves  which 
supply  the  nasal  cavities  are  the  olfactory  (which 


271 

pass  through  the  cribriform  plate  of  the  ethmoid 
bone),  the  internal  nasal  of  the  ophthalmic,  and 
branches  derived  from  Meckel's  ganglion. 

THE    ORGAN    OF    TASTE 

Is  of  triangular  form,  and  is  connected  by  its 
base  to  the  os  hyoides  by  folds  of  mucous  membrane 
to  the  epiglottis  and  palate,  and  by  muscles  to  the 
lower  jaw.  It  is  covered  with  mucous  membrane, 
on  which  are  situated  papilla?,  arranged  in  three 
varieties — the  filiform,  situated  at  the  tip  and  sides; 
the  fungiform,  scattered  over  the  dorsum ;  the  cir- 
cumvallataj,  from  eight  to  ten  in  number,  at  the 
back  of  the  dorsum.  It  is  covered  with  squamous 
epithelium.  The  tongue  is  composed  of  two  sym- 
metrical halves,  separated  by  a  fibrous  septum,  the 
muscles  composing  each  half  being  arranged  in  the 
following  order  :  genio-hyo-glossus,  lingualis,  hyo- 
glossus,  stylo-glossus,  palato-glossus,  and  superior 
constrictor.  It  is  highly  vascular,  and  receives  six 
nerves,  three  on  each  side — viz.,  the  gustatory 
from  the  fifth,  for  sensation ;  the  ninth  or  lingual, 
for  motion  ;  and  the  glosso-pharyngeal  connected 
with  the  special  sense  of  taste. 

THE   EYE    AND    ITS   APPENDAGES. 

The  appendages  of  the  eye  are  the  following : — 
The  lachrymal  gland,  placed  in  the  upper  and 


272 

outer  part  of  the  orbit,  behind  the  external  angular 
process  of  the  frontal  bone,  and  about  the  size  of 
a  small  almond,  is  of  greyish  colour,  consists  of 
numerous  lobules  united  by  an  imperfect  capsule, 
and  pours  forth  its  secretion  of  tears  by  means  of 
six  or  seven  minute  ducts,  which  open  behind  the 
upper  eyelid,  in  the  angle  formed  by  the  reflection 
of  the  conjunctiva. 

Conjunctiva,  a  mucous  membrane  which  lines 
the  interior  of  each  eyelid,  and  is  reflected  over  the 
anterior  part  of  the  globe  of 'the  eye.  At  the  inner 
angle  of  the  eye  it  forms  a  small  fold  called  plica 
semilunaris,  covers  the  caruncula  lachrymalis,  and 
having  lined  the  lachrj^mal  sac  and  duct,  becomes 
continuous  with  the  mucous  membrane  of  the  nose. 
The  epithelial  layer  of  this  membrane  is  continued 
over  the  cornea. 

Caruncula  lacJwpnaUs  is  a  small  vascular  body 
composed  of  mucous  glands  and  cellular  tissue 
situated  in  the  nasal  angle  of  the  eye,  and  covered 
by  the  membrana  conjunctiva. 

The  palpebrce,  or  eyelids,  semicircular  in  form, 
are  composed  of  skin  externally,  which  is  very  fine, 
the  tunica  conjunctiva  internally,  and  between 
both  the  orbicularis  palpebrarum  muscle,  the  tarsal 
cartilages  and  their  ligaments,  and  the  Meibomian 
glands,  together  with  blood-vessels,  nerves,  and 
absorbents. 

The  superior  eyelid,  besides  being  the  larger,  has 


273 

also  peculiar  to  it  the  levator  palpcbrflG  superioris 
muscle. 

The  tarsal  cartilages  are  thin  dense  connective 
tissue  plates,  of  a  semicircular  form,  the  superior 
being  the  larger  ;  to  their  convex  margins  are  at- 
tached the  palpebral  ligaments^  which  are  continua- 
tions of  the  orbital  periosteum. 

The  Meibomian  glands,  of  a  yellow  colour,  are 
very  numerous,  particularly  in  the  upper  eyelid, 
and  are  arranged  in  vertical  rows. 

The  opposed  edges  of  the  eyelids  are  thick,  and 
are  bevelled  off  obliquely  towards  the  eye,  so  that 
"when  closed  they  only  touch  at  their  anterior 
edges,  thus  leaving  a  triangular  canal,  the  base  of 
which  is  formed  by  the  tunica  conjunctiva,  along 
which  the  tears  are  conducted  to  the  puncta  lacliry- 
malia. 

The  cilia,  or  eyelashes,  attached  by  their  roots  to 
the  opposite  margins  of  the  eyelids,  observe  a  curved 
arrangement,  their  convexities  looking  towards 
each  other. 

The  puncta  lachrymalia  are  the  two  minute 
orifices  of  the  lachrymal  canals,  placed  within  two 
or  three  lines  of  the  nasal  terminations  of  the  eye- 
lids and  upon  their  opposed  edges. 

The  lachrymal  canals,  the  superior  of  which 
is  longer  and  curved,  the  inferior  being  nearly 
straight,  lead  from  the  puncta  lachrymalia  to  the 
lachrymal  sac. 

T 


274 

The  lachrymal  sac,  placed  in  the  fossa  formed  by 
the  lachrymal  and  superior  maxillary  bones  behind 
the  fibrous  expansion  from  the  tendon  of  the  orbi- 
cularis palpebrarum,  is  of  oval  form,  receives  the 
lachryinal  secretion  by  the  puncta  lachrymalia,  and 
transmits  it  to  the  nasal  duct,  with  which  it  is 
connected  inferiorly. 

The  nasol  duct,  enclosed  in  a  bony  canal,  formed 
by  the  lachrymal,  superior  maxillary,  and  inferior 
spongy  bones,  passes  obliquely  downwards,  back- 
wards, and  outwards,  and  terminates  in  the  inferior 
meatus  of  the  nose. 


THE   EYE 

Is  of  spherical  form,  and  is  composed  of  mem- 
branes or  tissues  enclosing  fluids,  called  humours. 

The  sclerotic  coat,  occupying  about  four-fifths  of 
the  globe,  is  a  strong,  white,  fibrous  structure,  and 
thicker  behind  and  anteriorly  than  in  its  centre. 
Its  outer  surface  is  in  contact  with  the  adipose 
tissue  of  the  orbit,  the  tendinous  expansions  of  the 
muscles  of  the  eye,  and  anteriorly  with  the  con- 
junctiva ;  its  inner  surface  is  lined  with  the  cho- 
roid coat.  It  presents  posteriorly  a  small  aperture, 
lamina  crihrosa,  for  the  transmission  of  the  optic 
nerve,  which  enters  at  the  nasal  side  of  the  centre, 


275 

and  an  anterior  large  one,  above  six  or  seven  lines 
in  diameter,  for  the  cornea. 

The  cornea,  which  forms  the  anterior  fifth  of  the 
globe,  is  smooth  and  transparent.  It  is  about  ijVof 
an  inch  in  thickness,  and  consists  of  five  layers — 
viz.,  the  conjunctival  layer  externally,  which  con- 
sists of  a  deeper  layer  of  rounded  cells,  and  a  super- 
ficial one  of  columnar  cells  with  flattened  bases ;  an 
anterior  homogeneous  lamina ;  the  central  fibrous 
layer,  composed  of  about  sixty  straight  lamellae  of 
connective  tissue,  whose  strata  lie  parallel  to  the 
surface  of  the  cornea ;  between  the  strata  are  a 
number  of  cell  spaces  filled  with  corneal  corpuscles, 
which  exhibit  amoeboid  movements  ;  a  posterior 
elastic  layer,  or  membrane  of  Demours,  about  jsVo 
of  an  inch  in  thickness,  elastic  and  structureless  ; 
and  most  internally  an  epithelial  lining.  Neither 
blood-vessels  nor  lymphatics  can  be  discovered 
in  a  healthy  cornea,  but  the  nerves  are  very 
abundant. 

The  choroid  coat  is  a  thin  vascular  membrane 
placed  between  the  sclerotic  coat  and  the  retina;  it 
extends  from  the  entrance  of  the  optic  nerve  to  tho 
ciliary  ligament,  to  which  it  is  firmly  attached ;  it 
is  then  directed  inwards  and  forms  the  folds  called 
ciliary  processes.  It  is  composed  of  three  layers, 
an  external  or  venous  plexus,  which  converge  to 
four  equidistant  trunks,  called  the  venae  vorticosae; 
t2 


276 

a  middle  or  fine  capillary  plexus,  the  tunica  Ruys- 
chiana ;  and  an  internal  or  pigmental  layer,  com- 
posed of  hexagonal  cells  containing  pigment  gra- 
nules. 

Between  the  tunica  Ruyschiana  and  the  pig'* 
mental  layer  is  a  thin  structureless  membrane,  the 
membrane  of  Bruch. 

The  ciliarij  processes  vary  in  number  from  sixty 
to  eighty,  and  are  formed  by  the  folding  backwards 
of  the  choroid  coat :  each  ciliary  process  is  of  trian- 
gular shape,  the  anterior  edge  being  attached  to 
the  ciliary  ligament,  the  posterior  being  free  and 
resting  upon  the  anterior  aspect  of  the  outer  border 
of  the  lens. 

The  ciliary  muscle;  formerly  described  as  the 
ciliary  ligament,  is  composed  of  unstriped  muscu- 
lar tissue  about  a  line  in  breadth.  It  is  placed 
close  to  the  junction  of  the  sclerotic  and  cornea, 
and  arises  from  the  inner  aspect  of  the  front  of  the 
sclerotic  by  a  thin  tendon :  from  this  its  fibres 
spread  out  in  a  radiating  manner  and  are  inserted 
into  the  choroid  opposite  to  the  ciliary  processes. 
At  the  junction  of  the  muscle  with  the  sclerotic 
there  is  a  small  circular  venous  canal  called  the 
canal  of  Schlemm. 

The  iris  is  a  circular  muscular  membrance  placed 
in  a  transverse  vertical  position,  attached  by  its 
larger  circumference  to  the  ciliarymuscle  floating 
in  the  aqueous  humour,  and  presenting  a  circular 


277 

opening  in  its  centre,  called  the  pupil.  It  divides 
the  space  between  the  anterior  surface  of  the  cap- 
sule of  the  lens  and  the  posterior  surface  of  the 
cornea,  unequally,  into  what  are  termed  the  chain- 
hcKs  of  the  aqueous  humour ,  the  anterior  chamber 
being  much  the  larger ;  both  chambers,  however, 
communicate  through  the  pupil.  The  anterior  sur- 
face of  the  iris  presents  a  radiated  appearance,  and, 
varies  in  colour  in  different  individuals  ;  the  posterior 
surface  is  covered  by  pigmcntum  nigrum,  which  has 
received  the  name  of  uvea. 

The  muscular  tissue  is  unstripcd  and  arranged 
into  two  sets,  having  circular  (sphincter)  and 
radiating  (dilatator)  fibres.  Pigment  cells  are 
found  throughout  the  whole  thickness  of  the  iris. 

Memhrana  pupillaris  is  a  transparent  membrane 
which  closes  the  pupil,  but  gradually  disappears 
from  the  seventh  month  of  foetal  life,  and  at  birth 
no  longer  exists.  It  is  supplied  with  vessels  de- 
rived from  the  iris  and  the  capsule  of  the  lens.  The 
iris  is  supplied  by  the  ciliary  vessel  and  nerves. 

The  retina,  the  expansion  of  the  optic  nerve,  is 
placed  between  the  choroid  and  the  hyaloid  mem- 
brane of  the  vitreous  humour,  and  terminates  in 
front  in  the  orra  serrata.  It  varies  in  thickness 
from  the  ^Vth  to  the  -jo-crth  of  an  inch.  It  is 
of  transparent  pink  colour,  but  rapidly  becomes 
opaque.  It  is  surrounded  externally  by  a  thin 
\i\yQv  of  hexagonal  pigment  cells,  sometimes    dc- 


278 

cribed  as  part  of  the  choroid.  The  retina  consists 
of  eight  layers,  which  from  without  inwards  are 
arranged  in  the  following  order : — 1,  a  layer  of  hex- 
agonal pigment  cells  ;  2,  the  layer  of  rods  and  cones 
the  bacillary  layer,  or  Jacobson's  membrane,  con- 
sisting of  rods  and  cones,  which  lie  parallel  to  each 
other  over  the  whole  of  the  retina  between  the  ex- 
ternal limiting  membrane  and  the  pigmentary  layer 
— the  rods  are  absent  at  the  yellow  spot ;  3,  the 
outer  nuclear  layer  ;  4,  the  outer  molecular  layer; 
5,  the  inner  nuclear  layer  ;  6,  the  inner  molecular 
layer ;  7,  the  ganglionic  or  nerve-cell  layer  ;  8,  the 
nerve  or  nerve-fibre  layer — this  latter  is  bounded 
internally  by  the  membrana  limitans  interna. 
Running  through  the  whole  thickness  of  the  retina 
are  the  Miillerian  or  radial  fibres,  which  rest  inter- 
nally upon  the  limiting  membrane,  and,  passing 
through  the  various  layers,  assume  diff'erent 
shapes,  and  ultimately  become  connected  with  the 
rods  and  cones. 

The  maculata  lutea,  situated  in  the  centre  of 
iho,  axis  of  vision,  is  a  round  spot  at  which  all  the 
layers  of  the  retina  are  thinner ;  there  are  no  rods  ; 
the  cones  are  longer  and  narrower. 

The  vascular  layer  is  formed  by  the  branchings 
of  the  arteria  centralis  retina). 

The  aqueous  humour  is  contained  in  the  anterior 
and  posterior  chambers  of  the  eye ;  is  perfectly 
transparent,  and  weighs  from  four  to  five  grains. 


It  contains  about  two  per  cent,  of  cliloride  of 
sodium. 

The  vitreous  humour  occupies  about  the  three 
posterior  fourths  of  the  eye;  it  is  contained  in  the 
hyaloid  membrane,  whicli  not  only  envelopes  it,  but 
sends  numerous  partitions  from  its  inner  surface  to 
form  cells  in  which  this  transparent  fluid  is  depo- 
sited. The  vitreous  humour  thus  contained  in  its 
capsule  is  convex  posteriorly  and  on  its  lateral  cir- 
cumference, but  presents  anteriorly  a  concavity  for 
the  reception  of  the  crystalline  lens :  around  the 
circumference  of  this  cavity  the  vitreous  humour 
presents  a  striated  appearance,  caused  by  the  marks 
of  the  ciliary  processes,  to  which  the  term  corona 
ciliaris,  or  zone  of  Zinn,  is  applied.  Running 
through  the  centre  of  the  vitreous  from  before  back- 
wards is  a  small  canal — canal  of  Stilling — broader 
behind  than  in  front. 

The  crystalline  lens^  enclosed  in  its  capsule  and 
placed  in  the  anterior  depression  of  the  vitreous 
humour,  is  a  transparent  body,  presenting  an  ante- 
rior and  a  posterior  convex  surface,  the  latter  being 
the  more  prominent.  Its  external  surface  is  soft 
and  pulpy,  gradually  increasing  in  density  towards 
its  centre.  It  is  composed  of  concentric  layers 
consisting  of  parallel  fibres  united  together  by 
wavy  margins,  the  fibres  being  hexagonal,  on  a 
transverse  section. 

The  capsule  of  this  body,  like  the  lens  itself,  is 


280 

transparent,  and  composed  of  homogeneous  mem- 
brane. 

The  lens  and  its  capsule  derive  their  nutriment 
from  the  vessels  of  the  hyaloid  membrane. 

Liquor  Morgagni  is  a  fluid  found  some  hours  after 
death  between  the  lens  and  its  capsule.  It  is 
the  soft  external  substance  of  the  lens. 

Canal  of  Petit. — The  lens  is  retained  in  its  situa- 
tion by  the  hyaloid  membrane,  which,  splitting  into 
two  laminae  at  its  circumference,  pass  one  anterior 
the  other  posterior  to  its  capsule ;  a  triangular 
canal  is  thus  formed,  which  is  intersected  by  min- 
ute septa :  this  is  the  canal  of  Petit,  and  may  be 
demonstrated  by  distending  it  with  air,  when  it 
will  present  a  vesicular  appearance. 

THE   ORGAN   OF   HEARING. 

This  organ  consists  of  the  external  ear,  includ- 
ing the  pinna  and  meatus  auditorius  externus ;  the 
middle  ear,  including  the  cavity  of  the  tympanum 
and  its  appendages  ;  and  the  internal  ear  or  laby- 
rinth, including  the  vestibule,  semicircular  canals, 
and  cochlea. 

The  external  ear  consists  of  a  fibro-cartilaginous 
plate  covered  by  skin,  and  so  moulded  as  to  form 
different  elevations  and  depressions. 

The  helix  is  the  semicircular  eminence  which 
forms  the  outline  of  the  external  ear. 


281 

The  anti-helix  commences  superiorly  by  two 
roots,  which  enclose  a  fossa  {fossa  of  the  anti-helix), 
and  is  situated  inferior  to  the  helix. 

The  tragus  is  an  eminence  placed  anterior  and 
inferior  to  the  meatus  externus. 

The  anti-tragus  is  a  smaller  eminence  posterior  to 
the  meatus  externus. 

The  lohule  is  a  pendulous  body  placed  underneath 
the  anti-tragus,  composed  of  adipose  and  cellular 
tissue. 

The  concha,  a  deep  conoidal  cavity  which  leads 
to  the  meatus  externus,  and  in  which  the  several 
depressions  formed  by  the  eminences  just  described 
terminate. 

Fossa  of  the  helix  is  a  curved  groove  between  the 
helix  and  anti-helix. 

Muscles  of  the  pinna  are : — 

M.  helicis  major,  in  front  of  helix. 

M.  helicis  minor,  from  concha  to  base  of  helix. 

M.  tragicus,  over  tragus. 

M.  anti-tragicus,  over  anti-tragus. 

M.  transversus  auriculce,  from  back  of  concha  to 
helix. 

M.  ohliquiis  auris,  at  back  of  concha. 

The  meatus  externus,  an  inch  and  a  quarter  in 
length,  is  a  curved  canal  which  leads  from  the 
concha  to  the  mcmbrana  tympana  ;  it  is  lined  by 
skin,  beneath  which  are  placed  small  glands 
{gla)iduloe  ceruminosce),  which  secrete  the  ear-wax 


283 

(cerumen).  The  outer  half  is  cartilaginous,  and  is 
formed  by  the  deep  part  of  the  pinna ;  the  inner 
portion  is  osseous,  at  the  bottom  of  which  is  a 
nearly  circular  groove  which  receives  the  mem- 
bran  a  tympani. 

The  memhrana  tympani,  separating  the  external 
from  the  middle  ear,  is  of  circular  form,  and  con- 
sists of  three  layers — ^\-iz.,  the  external  or  cuticular, 
the  internal  or  mucous,  and  between  both  a  fibrous 
layer.  To  its  inner  aspect  is  attached  the  handle 
of  the  malleus,  which,  by  drawing  it  towards  the 
middle  ear,  gives  it  a  concave  aspect  externally. 

The  middle  ear  consists  of  the  cavity  of  the  tym- 
panum and  the  small  bones  of  the  ear  and  their 
muscles. 

The  cavity  of  the  tympanum  is  an  irregular  space, 
closed  externally  by  the  membrana  tympani,  and 
bounded  internally  by  a  bony  partition,  which 
separates  it  from  the  labyrinth.  It  is  half  an  inch 
in  length  and  presents  six  walls — 

The  roof,  thin  and  bony. 

TheyZoor,  separated  from  the  jugular  fossa  by  a 
thin  plate  of  bone. 

The  outer  wall  presents  the  membrana  tympani, 
the  Glaserian  fissure,  and  foramen  chordae  an terius, 
which  gives  passage  to  chorda  tympani  nerve. 

The  inner  wall  presents  the  promontory,  a  con- 
vex eminence,  which  marks  the  situation  of  the 
first  turn  of  the  cochlea ;  i\iQ fenestra  ovalis,  placed 


283 

above  the  promontory,  and  to  which  the  base  of  the 
stapes  is  attached ;  the  fenestra  rotunday  below 
the  promontory,  closed  by  a  membrane,  which 
separates  the  scala  tympani  of  the  cochlea  from 
the  cavity  of  the  tympanum ;  the  aqueductus  Fal- 
lopii  for  the  facial  nerve. 

The  posterior  wall  presents  the  openings  of  the 
mastoid  cells ;  the  pyramid^  a  bony  projection, 
hollow  within,  and  containing  the  stapedius  mus- 
cle ;  the  foramen  chordae  posterius  for  the  exit  of 
the  chorda  tympani  nerve. 

The  anterior  wall  presents  the  openings  of  two 
bony  canals,  the  superior  lodges  the  tensor  tympani, 
the  inferior  forming  the  Eustachian  tube  ;  these 
are  separated  by  a  bony  septum,  the  processus 
cocJdeariformis. 

The  Eustachian  tube  is  a  tube  leading  from  the 
tympanum  to  the  pharynx,  and  is  about  an  inch 
and  a  half  long.  The  upper  part  is  osseous  ;  the 
lower  half  is  cartilaginous,  and  terminates  in  front 
in  a  trumpet-shaped  opening,  through  which  the 
mucous  membrane  is  continued  up  to  the  tym- 
panum. 

The  hones  of  the  ear  are  three  in  number,  very 
small,  and  contained  within  the  cavity  of  the  tym- 
panum. 

The  malleus  is  divided  into  the  head,  which  is 
smooth,  and  articulates  with  the  incus  ;  the  neck, 
which  is  small,  and  connects  the  head  to  the  shaft ; 


284 

the  handle  or  shaft,  which  descends  from  the  neck, 
and  is  attached  to  the  membrana  tjnipani,  and  the 
processus  gracilis,  which  passes  from  the  neck  to 
the  Glaserian  fissure. 

The  incus  is  divided  into  its  body,  which  presents 
a  cup-like  cavity  for  the  head  of  the  malleus  ;  a 
superior  process,  which  is  short  and  lies  in  the  mas- 
toid cells,  and  a  long  process,  to  the  extremity  of 
which  is  attached  a  small  process  of  bone  con- 
sidered by  some  as  a  distinct  bone,  and  called  os 
orbiculare. 

The  staj^es  presents  a  small  head,  which  is  at- 
tached to  the  orbicular  process  ;  a  short  neck ;  two 
curved  crura,  which  terminate  in  the  base ;  and  the 
base  itself,  which  is  of  oval  shape,  and  connected 
to  the  fenestra  ovalis. 
Ligaments  of  the  tympanum  are^- 
A7iterior  ligament  of  the  malleus  passes  from  the 
anterior  wall  to  the  base  of  the  processus  gracilis. 
Suspensory    ligament    of    the    malleus    descends 
from  the  roof  of  the  tympanum  to  the  head  of  the 
malleus. 

Posterior  ligament  of  the  incus  passes   from   the 
processus  brevis  of  the  incus  to  the  posterior  wall. 

Muscles  of  the  tympanum  are— ■ 
^  Tensor  tympani.—O.  bony  canal  in  petrous  por- 
tion of  temporal  bone.     7.  processus  brevis  of  mal- 
leus.    N.  from  otic  ganglion. 
Laxator  tympani.—O.  spine  of  sphenoid  bone. 


285 

/.  processus  gracilis  of  malleus.  N.  chorda  tym- 
pani. 

Stapedius,  from  cavity  of  pyramid.  /.  neck  of 
stapes.     N.  from  facial. 

The  tympanum  is  lined  with  mucous  membrane, 
continuous  with  the  pharynx,  and  prolonged  back- 
wards into  mastoid  cells,  and  is  reflected  over  the 
ossicula. 

The  internal  ear  or  labyrinth. 

The  vestibule,  placed  behind  the  cochlea  and  before 
the  semicircular  canals,  is  a  small  oval  cavity  about 
ith  of  an  inch  in  diameter,  lined  by  a  membrane  com- 
mon to  the  labyrinth,  contains  a  watery  fluid,  and 
presents  the  following  openings : — viz.,  on  its  outer 
wall,  the  fenestra  ovalis  ;  on  its  posterior  aspect, 
the  five  orifices  of  the  semicircular  canals  ;  on  its 
anterior  wall,  the  orifice  of  the  scala  vestibuli ;  on 
its  inner  wall,  the  aqueductus  vestibuli,  the  fovea 
hcmispherica,  and  also  the  fovea  hemi-elliptica ; 
and  between  them  the  eminentia  pyramidalis. 

The  semicircular  canals,  placed  behind  the  vesti- 
bule, are  three  in  number,  two  vertical  and  one  hori- 
zontal ;  of  the  former,  one  is  superior  and  the  other 
posterior.  The  openings  of  these  canals  are  only 
five  in  number,  in  consequence  of  one  opening  of 
the  vertical  canals  being  common  to  both.  Each 
semicircular  canal  at  one  end  presents  a  dilatation 
called  the  ampulla,  the  diameter  of  which  is  -rjth 
of  an  inch  ;  that  of  the  canals  is  2\jth. 


286 

The  cochlea,  of  conical  form,  the  base  towards 
the  internal  meatus,  the  apex  towards  the  carotid 
canal,  is  composed  of  a  bony  tube  which  makes  two 
turns  and  a  half  round  a  central  pillar  called  the 
modiolus.  This  tube  is  divided  longitudinally  by  a 
thin  plate,  half  bony,  half  membranous,  called 
lamina  spiralis,  into  two  independent  cavities,  the 
two  tubes  thus  formed  arc  called  the  scalae  of  the 
cochlea ;  they  both  unite  at  the  apex  in  a  cavity 
called  helicotrema,  and  at  the  base  of  the  cochlea 
they  separate,  one  called  scalavestihuli,  which  opens 
into  the  vestibule,  the  other  called  scala  tipnpaniy 
which  opens  into  the  tympanum  by  the  foramen 
rotundum.  From  the  scala  tympani  proceeds  a 
narrow  bony  canal  called  the  aqueduct  of  the  coch- 
lea, which  terminates  in  a  slit-like  opening  in  the 
inferior  border  of  the  petrous  bone. 

The  membranous  labyrinth  is  contained  within 
the  osseous  labyrinth,  and  assumes  in  the  main  a 
similar  shape  to  the  bones  within  which  it  lies.  In 
it  are  spread  out  the  divisions  of  the  auditory  nerve, 
separated  from  the  osseous  walls  by  perilymph,  and 
within  it  is  the  endolymph.  The  membranous  ves- 
tibule consists  of  two  sacs,  the  utricle  and  the- 
saccule^  which  are  lodged  respectively  in  the  fovea 
hemi-elliptica  and  fovea  hemispherica.  They  l^oth 
contain  small  granules  of  carbonate  of  lime  called 
otoUthes.       The    membranous     semicircular    cancds 


387 

correspond  in  shape  to  the  osseous  canals,  but  are 
about  one-third  of  their  diameter. 

The  auditory  nerve  reaches  the  inner  ear  by  small 
foramina  at  the  base  of  the  meatus  auditorius  inter- 
nus,  and  divides  into  two  trunks,  cocA/ear  and  vesti- 
bular. The  vestibular  breaks  up  into  five  branches, 
to  the  utricle,  saccule,  and  three  semicircular  canals, 
and  on  section  presents  three  layers,  an  external 
fibrous,  a  middle — the  tunica  propria — and  an  inner 
an  epithelial  lining. 

The  membranous  cochlear  lines  separately  the  two 
scalae.  The  osseous  lamina  spiralis  is  prolonged  to 
the  outer  wall  by  the  basilar  membrane,  with  which 
it  is  connected  by  the  ligamentum  spiraJe.  The 
scala  vestibuli  is  divided  by  a  very  thin  membrane 
obliquely  stretched  across  the  cavity,  membrane  oj 
Reissner,  into  two  nearly  equal  tubes,  the  inner 
one  being  the  scala  vestibuli,  the  outer,  the  ductus 
cochlear  is,  which  at  its  commencement  is  con- 
tinuous with  the  cavity  of  the  saccule  through  a 
small  canal,  canalis  reumens.  The  floor  of  the 
ductus  cochlearis  is  formed  by  the  membrana  tec- 
toria,  which  runs  parallel  with  and  above  the  basi- 
lar membrane,  and  between  them  are  contained 
the  following  structures,  beginning  from  within  :-thc 
thickened  end  of  the  lamina  spiralis,  called  the 
limbus,  which  overhangs  the  spiral  groove  ;  then  a 
layer  of  cells  external  to  these,  the  rods  ofCorti,  an 


288 

inner  and  an  outer  set,  which  arc  arranged  obliquely, 
so  that  their  upper  ends  support  each  other ;  the  cells 
internal  to  the  inner  rods  are  called  inner  haii'-cells, 
those  on  the  outer  side  the  outer  hair-cells ;  and  most 
external  of  all  is  the  ligamentum  spiraUy  sup- 
posed by  some  to  be  muscular  and  analogous  to  the 
ciliary  muscle. 

The  cocldear  division  of  the  auditory  nerv^e  enters 
the  canal  is  modiali,  giving  off  branches  which 
emerge  from  canals  in  the  lamina  spiralis,  and 
which,  after  being  connected  with  a  ganglion 
ramify  upon  the  membranous  lamina,  where  their 
termination  is  not  known. 


THE  ABSORBENT  SYSTEM 

Comprehends — 1st,  the  vessels  which  convey  the 
lymph  and  chyle  into  the  veins,  and  2nd,  the  en- 
largements which  occur  in  their  course,  called 
glands. 

The  lacteal  or  chyliferous  vessels  commence  on 
the  mucous  surface  of  the  intestines,  pass  through 
the  mesenteric  glands  backwards  towards  the 
spine,  where  they  terminate  in  the  thoracic  duct. 

The  lymphatic  vessels  are  found  in  most  situa- 
tions of  the  body,  and  generally  observe  a  deep  and 
superficial  arrangement. 


289 

Lymphatics  of  the  lower  extremities. — The  super- 
ficial set  accompany  the  external  and  internal  sa- 
phena  veins :  they  communicate  freely  in  their 
course  with  the  deep  lymphatic  trunks  wliicli  ac- 
company the  deep  vessels.  Those  which  ac- 
company the  external  saphena  vein  enter  the 
glands  in  the  popliteal  space,  whilst  those  accom- 
panying the  internal  saphena  vein  ascend  to  the 
groin,  and  pass  through  the  inguinal  glands,  having 
formed  numerous  connexions  with  the  superficial 
lymphatics  of  the  abdomen,  the  perineum,  and  the 
genitals.  The  deep  lymphatics  of  the  hip  and 
perineum  are  conducted  by  the  branches  of  the 
internal  iliac  vessels  into  the  pelvis,  and  pass 
through  the  pelvic  glands.  From  the  inguinal 
and  pelvic  glands  the  lymphatics  pass  along  the 
iliac  vessels  to  the  receptaculum  chyli. 

The  thoracic  duct. — This  canal  commences  by  a 
dilatation  called  receptaculum  chyli,  placed  on  the 
body  of  the  second  lumbar  vertebra  ;  passing  be- 
tween the  crura  of  the  diaphragm,  it  gains  the  pos- 
terior mediastinum,  where  it  lies  between  the  aorta 
and  the  vena  azygos;  at  the  fifth  dorsal  vestebra  it 
crosses  the  spine  obliquely  to  the  left  side,  passing 
behind  the  oesophagus  and  arch  of  the  aorta,  and 
placed  behind  the  left  pleura  and  between  the  left 
carotid  and  left  subclavian  arteries  ;  it  is  then  con- 
ducted by  the  oesophagus  to  the  left  side  of  the 
neck  as  high  as  the  sixth  cervical  vertebra,  wiicre, 


290 

making  a  slight  curve  downwards  and  outwards,  it 
opens  close  to  the  external  angle  formed  by  the 
left  subclavian  and  jugular  veins. 

Lymphatics  of  the  upper  extremities. — The  super- 
ficial set  accompany  the  superficial  veins  and 
pass  through  two  or  three  glands  situated  at  the 
inner  condvle  ;  having  joined  the  deep  lymphatics 
which  accompany  the  venae  comitcs,  they  proceed 
onwards  to  the  axilla,  and  pass  through  the  axil- 
lary glands ;  following  the  course  of  the  axillary 
vein,  they  pass  beneath  the  clavicle,  join  the  lym- 
phatics of  the  neck,  and  terminate  in  the  thoracic 
duct.  The  lymphatics  of  the  right  upper  extremity 
and  right  side  of  the  neck  unite  to  form  the  right 
or  lesser  lymphatic  duct,  which  opens  into  the  right 
vena  innominata. 

The  lymphatics  of  the  trunk  consist  of  a  deep 
and  superficial  set;  in  the  chest  the  former  are 
seated  between  the  muscles  and  pleura,  in  the 
abdomen  between  the  muscles  and  peritoneum,  the 
superficial  being  subcutaneous.  The  viscera  con- 
tained in  the  chest  and  abdomen  also  have  a  super- 
ficial and  deep  layer  of  lymphatics,  the  deep  being 
distributed  through  the  peculiar  tissue  of  each 
organ^  the  superficial  running  beneath  the  mem- 
branous envelope. 

Lymphatics  have 'been  seen  in  the  membranes, 
but  not  in  the  proper  substance,  of  the  brain  and 
spinal  cord. 


291 

PECITLIAEITIES  OF  THE  FCETUS. 

The  principal  anatomical  peculiarities  of  the 
fcetus,  bj'  wliich  it  is  distinguished  from  the  adult, 
are  the  following  : — 

The  tJiymxis  gland  occupies  the  anterior  medias- 
tinum,— the  kidnejjs  are  lobulated,  and  each  is 
covered  by  a  cellulo-vascular  body  called  supra- 
renal capsuhy  which  is  larger  than  the  kidney  it- 
self,— the  liver  is  very  large,  particularly  its  left 
lobe, — the  luyjgs  are  compact,  of  a  deep  red  colour, 
and  sink  in  water,  the  bronchial  tubes  and  their 
ramifications  being  void  of  air, — the  auricles  of  the 
heart  communicate  by  the  foramen  ovale, — at  the 
bifurcation  of  the  pulmonary  artery  an  arterial 
trunk,  about  nine  lines  in  length,  called  ductus 
arteriosus,  proceeds  to  the  aorta,  into  which  vessel 
it  opens, — the  unihillcal  vein  proceeds  to  the  liver, 
where,  having  distributed  some  branches  to  its  left 
lobe,  it  divides  into  the  communicating  branchy 
which  unites  with  the  portal  vein  and  the  ductus 
venosus,  which  opens  into  the  vena  cava  inferior,— 
the  internal  iliac  arteries,  under  the  name  of  um- 
bilical or  hypogastric,  turn  upwards  and  forwards 
along  the  sides  of  the  bladder,  pass  through  the 
umbilicus,  and  run  a  tortuous  course  along  the 
umbilical  vein  to  the  placenta, — and  the  urinary 
bladder  is  in  the  abdominal  part  of  the  pelvis,  from 
the  summit  of  which  a  ligamentous  cord,  once  a 
u2 


292 

tube,  called  urachus,  passes  to  the  umbilicus.  Until 
the  seventh  month  the  pupil  is  closed  by  a  mem- 
brane, called  membrana  ptipillaris,  and  in  the  male 
the  testes  are  contained  in  the  abdomen. 


THE  LARYNX. 

Besides  the  os  hyoides,  the  muscles,  ressels, 
nerves,  and  mucous  membrane  which  enter  into  the 
fonnation  of  the  laiynx,  there  are  four  cartilages 
and  one  fibi*o-eartilage.  The  os  hyoides  has  a  body  ; 
two  greater  and  two  lesser  cornua. 

The  thjroid  cartilage  presents  anteriorly  a  pro- 
minent angle  called  pomum  Adami\  which  is 
formed  by  the  meeting  of  its  alae.  Each  ala  is  of 
quadrilateral  form,  and  presents  posteriorly  two 
cornua ;  the  superior  cornu  is  the  longest,  and  is 
connected  to  the  great  cornu  of  the  os  hyoides  by 
the  thyro-hyoid  ligament ;  the  lesser,  or  inferior 
cornu,  being  connected  to  the  side  of  the  cricoid 
cartilage  by  synovial  membrane  and  ligaments. 

The  upper  margin  of  each  ala  is  connected  to  the 
OS  hyoides  by  the  thyro-hyoid  membrane,  the  infe- 
rior margin  being  connected  to  the  cricoid  cartilage 
by  the  crico-thyroid  membrane,  which  is  of  yellow 
colour  and  elastic ;  the  outer  surface  of  each  is 
rough,  and  divided  unequally  by  an  oblique  ridge. 


293 

the  inner  surface  being  smooth,  and  covered  by 
mucous  membrane. 

The  cricoid  cartilage  is  next  in  size,  and  forms  a 
ring ;  it  is  narrow  before  and  deep  behind  ;  its 
inferior  edge  is  connected  to  the  first  ring  of  the 
traehea ;  its  superior  ^(i^Q,  anteriorly,  is  connected 
by  the  crico-thyroid  ligament  to  the  thyroid  carti- 
lage :  posteriorly  it  supports  the  arytenoid  carti- 
lages ;  its  inner  surface  is  covered  by  mucous  mem- 
brane, and  its  outer  surface  is  rough,  and  presents 
posteriorly  a  vertical  ridge  for  the  attachment  of 
muscles. 

The  arytenoid  cartilages,  two  in  number,  and  of 
pyramidal  shape,  are  the  smallest ;  the  apex  of  each 
is  surmounted  by  a  small  moveable  cartilaginous 
appendix ;  the  base,  concave,  moves  upon  the 
cricoid  cartilage ;  the  posterior  surface,  concave, 
lodges  the  arytenoid  muscle,  the  external  edge  is 
convex  for  the  attachment  of  muscles,  and  the  in- 
ner edge  is  flat.  The  apex  of  each  is  connected  to 
the  epiglottis  by  a  fold  of  mucous  membrane  called 
the  aryteno-epiglotiidean  fold,  and  the  base  is  con- 
nected to  the  cricoid  cartilage  by  synovial  mem- 
brane and  ligaments. 

Cornicida  larijngis,  two  small  cartilaginous 
nodules,  above  the  arytenoid  cartilages,  and  con- 
tained in  the  arytcno-epiglottidean  fold. 

Cuneiform  cartilages,  two  long  cartilages  also 
contained  in  the  same  fold. 


294 

The  epiglottis,  composed  of  yellow  fibro-cartilage 
like  a  leaf  in  shape,  is  connected  by  its  stalk-like 
process  to  the  angle  of  the  thyroid  cartilage,  an- 
teriorly'to  the  hyoid  bone  by  the  hyo-epiglottidean 
ligament,  and  to  the  base  of  the  tongue  by  three 
folds  of  mucous  membrane,  the  central  one  of 
which  is  called  froenum  epiglotticUs ;  posteriorly 
extend  the  aryteno-epiglottidean  folds  of  mucous 
membrane. 

The  upper  opening  of  the  larynx  is  triangular 
with  its  base  forwards,  bounded  anteriorly  by  the 
base  of  the  epiglottis,  laterally  by  the  aryteno-epi- 
glottidean folds,  and  posteriorly  by  the  arytenoid 
cartilage. 

The  glottis,  or  the  rima  gloltidis,  is  of  triangular 
shape,  the  base  is  posterior,  and  is  formed  by  the 
bases  of  the  arytenoid  cartilages  ;  the  apex  is  ante- 
rior, corresponding  to  the  angle  formed  by  the  alse 
of  the  thyroid  cartilage,  and  the  sides  are  formed 
by  the  chordae  vocales. 

False  vocal  cords,  or  superior,  are  formed  by 
crescentic  folds  of  mucous  membrane  ;  within  each 
is  a  thin  ligament,  the  superior  thyro-arytcnoid 
ligament. 

True  vocal  cords,  or  inferior,  two  in  number, 
arise  from  the  anterior  aspect  of  arytenoid  cartilages, 
and  approaching  each  other  are  inserted  in  the 
angle  formed  by  the  alae  of  the  thyroid  cartilage. 
Each  ligament  is  composed  of  yellow  elastic  tissue. 


295  . 

Ventricle  of  the  larynx,  is  the  depression  be- 
tween the  false  and  true  vocal  cords,  and  leads  to 
a  small  pouch,  the  sacculus  larijngis,  which  extends 
upwards  between  the  thyroid  cartilag-e  and  supe- 
rior vocal  cord,  and  contains  a  large  number  of 
muciparous  glands. 

Muscles  already  described. 

Crico -thyroid  m.  renders  tense  the  vocal  cords. 

Crico-arytenoideus  posticus  m.  dilates  the  glottis, 
by  separating  the  vocal  cords. 

Crico-arytenoideus  lateralis  m.  closes  the  glottis 
.by  rotating  inwards  the  arytenoid  cartilages. 

Arytenoideus  m.  closes  the  glottis  by  approxi- 
mating the  arytenoid  cartilage. 

Thyro-aryienoideus  vi.  relaxes  the  vocal  cords 
by  approximating  the  thyroid  and  arytenoid  carti- 
lages. 

Aryteno-epiylottideus  superior  is  found  in  aryteno- 
epiglottidean  fold. 

Aryteno-epiglottideus  inferior,  or  Hilton's  muscle, 
passes  from  the  upper  part  of  arytenoid  cartilage 
to  the  margin  of  the  epiglottis. 

The  larynx  is  lined  with  mucous  membrane 
covered  with  ciliated  epithelium. 

All  the  muscles  of  the  larynx  are  supplied  by  the 
recurrent  laryngeal neiwe,  except  the  crico-thyroid, 
which  is  supplied  by  the  external  laryngeal  nerve. 


296 


THE  THYROID  BODY, 

Of  reddish-brown  colour,  consists  of  two  lateral 
lobes  and  a  connecting  middle  lobe  or  isthmus. 
The  lateral  lobes  are  placed  by  the  sides  of  the 
trachea  and  larynx,  and  the  isthmus  rests  upon  the 
anterior  aspect  of  the  two  or  three  first  rings  of  the 
trachea.  Each  lateral  lobe  is  of  pyriform  shape, 
the  base  inferior,  and  the  apex  ascending  to  the 
thyroid  cartilage  ;  both  lateral  lobes  overlap  the 
carotid  vessels,  the  inferior  thyroid  artery,  and  the 
recurrent  nerve  :  and  are  covered  by  the  sterno- ' 
hyoid,  sterno-thyroid,  and  omo-hyoid  muscles,  the 
cervical  fascia,  and  the  integuments.  This  body 
or  gland  is  supplied  with  blood  by  the  superior 
thyroid  art  ries  from  the  external  carotid,  the  in- 
ferior thyroid  arteries  from  the  thyroid  axis,  which 
is  a  branch  of  the  subclavian  artery,  and  some- 
times by  an  artery  from  the  arteria  innominata,  or 
from  the  aorta  itself,  called  the  middle  thyroid 
artery ;  its  blood  is  returned  by  the  thyroid  veins, 
which,  the  middle  descending  on  the  anterior  aspect 
of  the  trachea,  empty  themselves  into  the  left  vena 
innominata.  The  superior  and  inferior  cross  the 
common  carotid,  and  open  into  the  internal  jugu- 
lar. Its  nerves  come  from  the  laryngeal  branch  of 
the  pneumogastric,  and  from  the  sympathetic.  It 
consists  of  a  number  of  vesicles  connected  together 


297 

by  a  fibrous  stroma,  in  which  ramify  the  small  ar- 
teries. The  vesicles  contain  a  glairy  fluid,  in 
which  are  found  nuclei,  cells,  and  granular  matter. 
It  has  no  excretory  duct. 


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